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• 31. [Article] Improving nitrogen management with cover crops in organic broccoli production

  Legume cover crops can serve as important sources of nitrogen (N) in sustainable agriculture and can be economically beneficial when fertilizer inputs are reduced without a yield reduction. Synchronizing ...

  Citation × Citation Citation Abstract Copy Title: Improving nitrogen management with cover crops in organic broccoli production Author: Garrett, Amy (Amy Michelle) Legume cover crops can serve as important sources of nitrogen (N) in sustainable agriculture and can be economically beneficial when fertilizer inputs are reduced without a yield reduction. Synchronizing N mineralization from organic materials with the needs of the subsequent crop is a challenge for organic growers. Predicting plant available nitrogen from cover crop residue enables N fertilizer inputs to be adjusted for optimum economic yield and reduced environmental risk. An experiment was conducted near Corvallis, OR in 2006 through 2008 to evaluate cover crop and N effects in organic broccoli production in western Oregon. The specific objectives of this experiment were to: 1) evaluate biomass production and N accumulation from selected cover crop treatments; 2) compare the effects of selected cover crops grown as sole crops and as mixtures on broccoli yield, yield components, and net economic benefit; 3) estimate the quantity of feather meal N replaced by cover crops 4) estimate plant available nitrogen from cover crop residue in an organic broccoli production system; 5) evaluate soil NO₃₋N and petiole NO₃₋N as predictors of broccoli yield; and 6) evaluate models derived from laboratory incubation of cover crop residue to predict apparent nitrogen recovery (ANR) from cover crop residue in the field. The cover crop treatments included common vetch (Vicia sativa), phacelia (Phacelia tanacetifolia), 'Monida' oats (Avena sativa L.), phacelia plus common vetch, and 'Monida' oats plus common vetch. A fallow treatment was used as the control. Prior to incorporation, cover crop samples were collected from each block and frozen for later use in laboratory aerobic incubations. After the cover crops were flail-mowed and incorporated, four N rates (0, 100, 200, and 300 kg N ha⁻¹) were randomized within each cover crop treatment in a split plot design. All cover crop treatments produced much less biomass and accumulated less N in 2008 than in 2007. Planting vetch with oats or phacelia increased biomass production and N accumulation compared to sole crops in 2007 but not in 2008. Common vetch as a sole crop or in a mixture increased broccoli yield with 0 and 100 kg N ha⁻¹ applied compared to fallow. Legume cover crop mixtures with 100 kg N ha⁻¹ produced similar net economic returns for organic compared to fallow treatments with 300 kg N ha⁻¹. Nitrogen fertilizer input can be reduced by at least 100 kg N ha⁻¹ if common vetch is in the mixture and produces more than 5000 kg ha⁻¹ of biomass (130-180 kg N ha⁻¹). Vetch as a sole crop produced higher levels of soil NO₃₋N than the fallow treatments up to 80 days after soil incorporation in 2007. Oats and phacelia as sole crops, however, reduced soil NO₃₋N compared to fallow for up to 68 days after incorporation. Vetch mixtures with oats or phacelia produced intermediate levels of soil NO₃₋N between vetch as a sole crop and the fallow. Treatment effects were similar in 2008, but differences were less due to reduced cover crop biomass compared to 2007. Broccoli petiole nitrate levels were not affected by cover crop treatment in 2007, and there was no correlation with yield. In 2008, the oat cover crop treatment reduced broccoli petiole nitrate levels compared to the fallow. Petiole nitrate levels were strongly correlated with broccoli yield, with highest yields associated with petiole NO₃₋ N greater than 10,000 ppm. In the aerobic incubations with cover crop mixtures, a quadratic model described the relationship of percent N in the mixture to the apparent nitrogen recovery (ANR) at both 4 and 10 weeks. The highest ANR (about 40 percent) was similar for both extraction days. Net mineralization occurred when the percent N of the cover crop mixture was 1.5-1.8 percent. There was a strong correlation in 2007 between the ANR predicted by the incubation-derived model and the ANR in the soil and in the aboveground broccoli biomass. The model over predicted the ANR in the field soil, however the model more accurately predicted ANR in the broccoli biomass. The incubation model correctly predicted negative ANR values for the oat and phacelia cover-crop treatments. In 2008, the laboratory-predicted ANR and the field soil ANR were correlated (r²=.45), and the laboratory model over predicted the field ANR. The incubation model gave a poor prediction of broccoli biomass ANR. Title: Improving nitrogen management with cover crops in organic broccoli production Author: Garrett, Amy (Amy Michelle) Legume cover crops can serve as important sources of nitrogen (N) in sustainable agriculture and can be economically beneficial when fertilizer inputs are reduced without a yield reduction. Synchronizing N mineralization from organic materials with the needs of the subsequent crop is a challenge for organic growers. Predicting plant available nitrogen from cover crop residue enables N fertilizer inputs to be adjusted for optimum economic yield and reduced environmental risk. An experiment was conducted near Corvallis, OR in 2006 through 2008 to evaluate cover crop and N effects in organic broccoli production in western Oregon. The specific objectives of this experiment were to: 1) evaluate biomass production and N accumulation from selected cover crop treatments; 2) compare the effects of selected cover crops grown as sole crops and as mixtures on broccoli yield, yield components, and net economic benefit; 3) estimate the quantity of feather meal N replaced by cover crops 4) estimate plant available nitrogen from cover crop residue in an organic broccoli production system; 5) evaluate soil NO₃₋N and petiole NO₃₋N as predictors of broccoli yield; and 6) evaluate models derived from laboratory incubation of cover crop residue to predict apparent nitrogen recovery (ANR) from cover crop residue in the field. The cover crop treatments included common vetch (Vicia sativa), phacelia (Phacelia tanacetifolia), 'Monida' oats (Avena sativa L.), phacelia plus common vetch, and 'Monida' oats plus common vetch. A fallow treatment was used as the control. Prior to incorporation, cover crop samples were collected from each block and frozen for later use in laboratory aerobic incubations. After the cover crops were flail-mowed and incorporated, four N rates (0, 100, 200, and 300 kg N ha⁻¹) were randomized within each cover crop treatment in a split plot design. All cover crop treatments produced much less biomass and accumulated less N in 2008 than in 2007. Planting vetch with oats or phacelia increased biomass production and N accumulation compared to sole crops in 2007 but not in 2008. Common vetch as a sole crop or in a mixture increased broccoli yield with 0 and 100 kg N ha⁻¹ applied compared to fallow. Legume cover crop mixtures with 100 kg N ha⁻¹ produced similar net economic returns for organic compared to fallow treatments with 300 kg N ha⁻¹. Nitrogen fertilizer input can be reduced by at least 100 kg N ha⁻¹ if common vetch is in the mixture and produces more than 5000 kg ha⁻¹ of biomass (130-180 kg N ha⁻¹). Vetch as a sole crop produced higher levels of soil NO₃₋N than the fallow treatments up to 80 days after soil incorporation in 2007. Oats and phacelia as sole crops, however, reduced soil NO₃₋N compared to fallow for up to 68 days after incorporation. Vetch mixtures with oats or phacelia produced intermediate levels of soil NO₃₋N between vetch as a sole crop and the fallow. Treatment effects were similar in 2008, but differences were less due to reduced cover crop biomass compared to 2007. Broccoli petiole nitrate levels were not affected by cover crop treatment in 2007, and there was no correlation with yield. In 2008, the oat cover crop treatment reduced broccoli petiole nitrate levels compared to the fallow. Petiole nitrate levels were strongly correlated with broccoli yield, with highest yields associated with petiole NO₃₋ N greater than 10,000 ppm. In the aerobic incubations with cover crop mixtures, a quadratic model described the relationship of percent N in the mixture to the apparent nitrogen recovery (ANR) at both 4 and 10 weeks. The highest ANR (about 40 percent) was similar for both extraction days. Net mineralization occurred when the percent N of the cover crop mixture was 1.5-1.8 percent. There was a strong correlation in 2007 between the ANR predicted by the incubation-derived model and the ANR in the soil and in the aboveground broccoli biomass. The model over predicted the ANR in the field soil, however the model more accurately predicted ANR in the broccoli biomass. The incubation model correctly predicted negative ANR values for the oat and phacelia cover-crop treatments. In 2008, the laboratory-predicted ANR and the field soil ANR were correlated (r²=.45), and the laboratory model over predicted the field ANR. The incubation model gave a poor prediction of broccoli biomass ANR. Close

• 32. [Article] A production function analysis of water resource productivity in Pacific Northwest agriculture

  The competition or rivalry for the use of water resources among economic sectors of the Pacific Northwest and among geographical regions of the western United States has intensified in recent years. This ...

  Citation × Citation Citation Abstract Copy Title: A production function analysis of water resource productivity in Pacific Northwest agriculture Author: Holloway, Milton L. The competition or rivalry for the use of water resources among economic sectors of the Pacific Northwest and among geographical regions of the western United States has intensified in recent years. This rivalry and the long run prospects for water shortages have increased the demand for research concerning the productivity of this resource in alternative uses. This demand exists because the distribution and use of water resources require investment which typically comes from both public and private sources. Private and public planning groups seek answers to questions regarding future water resource development alternatives. Agriculture has historically been a major user of water in the Pacific Northwest. A substantial portion of total investment in water resource development has also been, in agriculture. As a result water use planners and decision making bodies are necessarily interested in water use in agriculture. The success of water resource planning requires answers to questions regarding the value of the productivity of water in all its major uses, including various aspects of water use in agriculture. Different aspects of water use in agriculture which are important to decision makers include (1) the value productivity of various kinds or types of water resource investments, (2) the value productivity of water in various kinds of agricultural production in different geographical areas, and (3) the returns to private and public investment in agricultural water resources. This study was directed to providing answers to these questions. Pacific Northwest agriculture was studied from this viewpoint. Agricultural water resources were classified as irrigation, drainage, and water related Agricultural Conservation Program (ACP) practices. These are the major classifications of water resources in which investments are made in the Pacific Northwest. Production function analysis was selected as a method of investigation. Production functions were estimated for five areas or subregions in the Pacific Northwest. These areas are composed of counties with similar patterns of production. The Agricultural Census was the primary data surce, supplemented by related U.S. Department of Agriculture publications, and various state publications, Ordinary least-squares regression (OLS) techniques were employed to derive the initial estimates of the parameters of the production function models. Tests for detecting interdependence within the independent variable set of the models revealed a considerable degree of instability in the OLS parameter estimates. This condition makes the OLS solutions (and various derivations) particularly vulnerable to change from measurement error, poor model specification, and equation form. A prior information model was selected to explicitly include available prior knowledge in the estimation process. The model selected allows (1) tests of comparability of the two information sources (prior and sample), (2) over-all contribution of prior information to the new solution set, and (3) derivation of percentage contribution of the two information sources to individual parameter estimates. The results of the study indicate that no reliable estimates of value of production from drainage and ACP were possible from the sample information. Returns to irrigation were considered lower than expected in two of the farming areas and higher than expected in another. Estimated returns were high in the area which produces primarily field crops (about nine dollars per acre foot). The area has a small level of current irrigation development. Indications are that irrigation development is probably beyond the optimum level in the area where most large, projects have been developed in the past (less than four dollars per acre foot). Future development would be most profitable (assuming equal development cost) in the dryland field crop area. Estimated returns to other factor inputs indicate (1) low returns to labor in two areas, (2) generally high returns to current operating expenditures, and (3) low returns to machinery capital. Returns to cropland were about as expected in two areas (five to seven percent) but low in two other areas (about two percent). Indications are that labor mobility should be increased in the area and that future land development should be in the livestock-field crop and the field crop areas rather than the coastal area or the west-central valley areas (primarily the Willamette Valley). Title: A production function analysis of water resource productivity in Pacific Northwest agriculture Author: Holloway, Milton L. The competition or rivalry for the use of water resources among economic sectors of the Pacific Northwest and among geographical regions of the western United States has intensified in recent years. This rivalry and the long run prospects for water shortages have increased the demand for research concerning the productivity of this resource in alternative uses. This demand exists because the distribution and use of water resources require investment which typically comes from both public and private sources. Private and public planning groups seek answers to questions regarding future water resource development alternatives. Agriculture has historically been a major user of water in the Pacific Northwest. A substantial portion of total investment in water resource development has also been, in agriculture. As a result water use planners and decision making bodies are necessarily interested in water use in agriculture. The success of water resource planning requires answers to questions regarding the value of the productivity of water in all its major uses, including various aspects of water use in agriculture. Different aspects of water use in agriculture which are important to decision makers include (1) the value productivity of various kinds or types of water resource investments, (2) the value productivity of water in various kinds of agricultural production in different geographical areas, and (3) the returns to private and public investment in agricultural water resources. This study was directed to providing answers to these questions. Pacific Northwest agriculture was studied from this viewpoint. Agricultural water resources were classified as irrigation, drainage, and water related Agricultural Conservation Program (ACP) practices. These are the major classifications of water resources in which investments are made in the Pacific Northwest. Production function analysis was selected as a method of investigation. Production functions were estimated for five areas or subregions in the Pacific Northwest. These areas are composed of counties with similar patterns of production. The Agricultural Census was the primary data surce, supplemented by related U.S. Department of Agriculture publications, and various state publications, Ordinary least-squares regression (OLS) techniques were employed to derive the initial estimates of the parameters of the production function models. Tests for detecting interdependence within the independent variable set of the models revealed a considerable degree of instability in the OLS parameter estimates. This condition makes the OLS solutions (and various derivations) particularly vulnerable to change from measurement error, poor model specification, and equation form. A prior information model was selected to explicitly include available prior knowledge in the estimation process. The model selected allows (1) tests of comparability of the two information sources (prior and sample), (2) over-all contribution of prior information to the new solution set, and (3) derivation of percentage contribution of the two information sources to individual parameter estimates. The results of the study indicate that no reliable estimates of value of production from drainage and ACP were possible from the sample information. Returns to irrigation were considered lower than expected in two of the farming areas and higher than expected in another. Estimated returns were high in the area which produces primarily field crops (about nine dollars per acre foot). The area has a small level of current irrigation development. Indications are that irrigation development is probably beyond the optimum level in the area where most large, projects have been developed in the past (less than four dollars per acre foot). Future development would be most profitable (assuming equal development cost) in the dryland field crop area. Estimated returns to other factor inputs indicate (1) low returns to labor in two areas, (2) generally high returns to current operating expenditures, and (3) low returns to machinery capital. Returns to cropland were about as expected in two areas (five to seven percent) but low in two other areas (about two percent). Indications are that labor mobility should be increased in the area and that future land development should be in the livestock-field crop and the field crop areas rather than the coastal area or the west-central valley areas (primarily the Willamette Valley). Close

• 33. [Article] A production function analysis of water resource productivity in Pacific Northwest agriculture

  The competition or rivalry for the use of water resources among economic sectors of the Pacific Northwest and among geographical regions of the western United States has intensified in recent years. This ...

  Citation × Citation Citation Abstract Copy Title: A production function analysis of water resource productivity in Pacific Northwest agriculture Author: Holloway, Milton L. The competition or rivalry for the use of water resources among economic sectors of the Pacific Northwest and among geographical regions of the western United States has intensified in recent years. This rivalry and the long run prospects for water shortages have increased the demand for research concerning the productivity of this resource in alternative uses. This demand exists because the distribution and use of water resources require investment which typically comes from both public and private sources. Private and public planning groups seek answers to questions regarding future water resource development alternatives. Agriculture has historically been a major user of water in the Pacific Northwest. A substantial portion of total investment in water resource development has also been in agriculture. As a result water use planners and decision making bodies are necessarily interested in water use in agriculture. The success of water resource planning requires answers to questions regarding the value of the productivity of water in all its major uses, including various aspects of water use in agriculture. Different aspects of water use in agriculture which are important to decision makers include (1) the value productivity of various kinds or types of water resource investments, (2) the value productivity of water in various kinds of agricultural production in different geographical areas, and (3) the returns to private and public investment in agricultural water resources. This study was directed to providing answers to these questions. Pacific Northwest agriculture was studied from this viewpoint. Agricultural water resources were classified as irrigation, drainage, and water related Agricultural Conservation Program (ACP) practices. These are the major classifications of water resources in which investments are made in the Pacific Northwest. Production function analysis was selected as a method of investigation. Production functions were estimated for five areas or subregions in the Pacific Northwest. These areas are composed of counties with similar patterns of production. The Agricultural Census was the primary data source, supplemented by related. U. S. Department of Agriculture publications, and various state publications. Ordinary least-squares regression (OLS) techniques were employed to derive the initial estimates of the parameters of the production function models. Tests for detecting interdependence within the independent variable set of the models revealed a considerable degree of instability in the OLS parameter estimates. This condition makes the OLS solutions (and various derivations) particularly vulnerable to change from measurement error, poor model specification, and equation form. A prior information model was selected to explicitly include available prior knowledge in the estimation process. The model selected allows (1) tests of comparability of the two information sources (prior and sample), (2) over-all contribution of prior information to the new solution set, and (3) derivation of percentage contribution of the two information sources to individual parameter estimates. The results of the study indicate that no reliable estimates of value of production from drainage and ACP were possible from the sample information. Returns to irrigation were considered lower than expected in two of the farming areas and higher than expected in another. Estimated returns were high in the area which produces primarily field crops (about nine dollars per acre foot). The area has a small level of current irrigation development. Indications are that irrigation development is probably beyond the optimum level in the area where most large projects have been developed in the past (less than four dollars per acre foot). Future development would be most profitable (assuming equal development cost) in the dryland field crop area. Estimated returns to other factor inputs indicate (1) low returns to labor in two areas, (2) generally high returns to current operating expenditures, and (3) low returns to machinery capital. Returns to cropland were about as expected in two areas (five to seven percent) but low in two other areas (about two percent). Indications are that labor mobility should be increased in the area and that future land development should be in the livestock-field crop and the field crop areas rather than the coastal area or the west-central valley areas (primarily the Willamette Valley). Title: A production function analysis of water resource productivity in Pacific Northwest agriculture Author: Holloway, Milton L. The competition or rivalry for the use of water resources among economic sectors of the Pacific Northwest and among geographical regions of the western United States has intensified in recent years. This rivalry and the long run prospects for water shortages have increased the demand for research concerning the productivity of this resource in alternative uses. This demand exists because the distribution and use of water resources require investment which typically comes from both public and private sources. Private and public planning groups seek answers to questions regarding future water resource development alternatives. Agriculture has historically been a major user of water in the Pacific Northwest. A substantial portion of total investment in water resource development has also been in agriculture. As a result water use planners and decision making bodies are necessarily interested in water use in agriculture. The success of water resource planning requires answers to questions regarding the value of the productivity of water in all its major uses, including various aspects of water use in agriculture. Different aspects of water use in agriculture which are important to decision makers include (1) the value productivity of various kinds or types of water resource investments, (2) the value productivity of water in various kinds of agricultural production in different geographical areas, and (3) the returns to private and public investment in agricultural water resources. This study was directed to providing answers to these questions. Pacific Northwest agriculture was studied from this viewpoint. Agricultural water resources were classified as irrigation, drainage, and water related Agricultural Conservation Program (ACP) practices. These are the major classifications of water resources in which investments are made in the Pacific Northwest. Production function analysis was selected as a method of investigation. Production functions were estimated for five areas or subregions in the Pacific Northwest. These areas are composed of counties with similar patterns of production. The Agricultural Census was the primary data source, supplemented by related. U. S. Department of Agriculture publications, and various state publications. Ordinary least-squares regression (OLS) techniques were employed to derive the initial estimates of the parameters of the production function models. Tests for detecting interdependence within the independent variable set of the models revealed a considerable degree of instability in the OLS parameter estimates. This condition makes the OLS solutions (and various derivations) particularly vulnerable to change from measurement error, poor model specification, and equation form. A prior information model was selected to explicitly include available prior knowledge in the estimation process. The model selected allows (1) tests of comparability of the two information sources (prior and sample), (2) over-all contribution of prior information to the new solution set, and (3) derivation of percentage contribution of the two information sources to individual parameter estimates. The results of the study indicate that no reliable estimates of value of production from drainage and ACP were possible from the sample information. Returns to irrigation were considered lower than expected in two of the farming areas and higher than expected in another. Estimated returns were high in the area which produces primarily field crops (about nine dollars per acre foot). The area has a small level of current irrigation development. Indications are that irrigation development is probably beyond the optimum level in the area where most large projects have been developed in the past (less than four dollars per acre foot). Future development would be most profitable (assuming equal development cost) in the dryland field crop area. Estimated returns to other factor inputs indicate (1) low returns to labor in two areas, (2) generally high returns to current operating expenditures, and (3) low returns to machinery capital. Returns to cropland were about as expected in two areas (five to seven percent) but low in two other areas (about two percent). Indications are that labor mobility should be increased in the area and that future land development should be in the livestock-field crop and the field crop areas rather than the coastal area or the west-central valley areas (primarily the Willamette Valley). Close

• 34. [Article] Influence of different nitrogen and moisture levels on the expression of grain yield and protein content in selected wheat (Triticum aestivum, L. em Thell) and barley (Hordeum vulagre, L. em Lam.) cultivars

  This investigation was conducted to provide information regarding 1) the relationship between the nitrogen percentage in the vegetative tissue of wheat and barley at various growth stages with grain protein and ...

  Citation × Citation Citation Abstract Copy Title: Influence of different nitrogen and moisture levels on the expression of grain yield and protein content in selected wheat (Triticum aestivum, L. em Thell) and barley (Hordeum vulagre, L. em Lam.) cultivars Author: Gomez-Pando, Luz This investigation was conducted to provide information regarding 1) the relationship between the nitrogen percentage in the vegetative tissue of wheat and barley at various growth stages with grain protein and 2) to evaluate the possible association between grain yield and grain protein as influenced by different cultivars, nitrogen levels and available moisture. Five wheat and four barley cultivars were selected based on their diverse genetic backgrounds and potential differences for the 12 attributes measured. These experimental materials were grown at low and high rainfall sites and under two different nitrogen levels. In wheat a decrease in the percentage of nitrogen in the flag leaves was found as the plants developed. The highest values were observed at the boot stage. In contrast, the highest percentage of nitrogen in the flag leaves of barley was observed at anthesis. Wheat cultivars which had the greatest genetic potential for grain protein usually had the highest percentage of nitrogen in the flag leaves at the boot stage and the lowest percentage in the vegetative tissue at harvest. This was especially true under high rainfall conditions. A similar relationship was found for the barley cultivars. At both experimental sites higher grain yields were accompanied by negative associations with grain protein for wheat. However, for barley no association was found between these two traits at either site or fertility level. Higher grain protein values were found for both wheat and barley at the high rainfall site. Title: Influence of different nitrogen and moisture levels on the expression of grain yield and protein content in selected wheat (Triticum aestivum, L. em Thell) and barley (Hordeum vulagre, L. em Lam.) cultivars Author: Gomez-Pando, Luz This investigation was conducted to provide information regarding 1) the relationship between the nitrogen percentage in the vegetative tissue of wheat and barley at various growth stages with grain protein and 2) to evaluate the possible association between grain yield and grain protein as influenced by different cultivars, nitrogen levels and available moisture. Five wheat and four barley cultivars were selected based on their diverse genetic backgrounds and potential differences for the 12 attributes measured. These experimental materials were grown at low and high rainfall sites and under two different nitrogen levels. In wheat a decrease in the percentage of nitrogen in the flag leaves was found as the plants developed. The highest values were observed at the boot stage. In contrast, the highest percentage of nitrogen in the flag leaves of barley was observed at anthesis. Wheat cultivars which had the greatest genetic potential for grain protein usually had the highest percentage of nitrogen in the flag leaves at the boot stage and the lowest percentage in the vegetative tissue at harvest. This was especially true under high rainfall conditions. A similar relationship was found for the barley cultivars. At both experimental sites higher grain yields were accompanied by negative associations with grain protein for wheat. However, for barley no association was found between these two traits at either site or fertility level. Higher grain protein values were found for both wheat and barley at the high rainfall site. Close

• 35. [Article] Developing Winter Food Barley for the Pacific Northwest of the US

  This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the Crop Science Society of America and can be found at: https://dl.sciencesoci...

  Citation × Citation Citation Abstract Copy Title: Developing Winter Food Barley for the Pacific Northwest of the US Author: Kongraksawech, Teepakorn, Meints, Brigid, Cuesta-Marcos, Alfonso, Hayes, Patrick M., Marshall, Juliet M., Fisk, Scott, Ross, Andrew S., Murphy, Kevin This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the Crop Science Society of America and can be found at: https://dl.sciencesocieties.org/publications/cs Title: Developing Winter Food Barley for the Pacific Northwest of the US Author: Kongraksawech, Teepakorn, Meints, Brigid, Cuesta-Marcos, Alfonso, Hayes, Patrick M., Marshall, Juliet M., Fisk, Scott, Ross, Andrew S., Murphy, Kevin This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the Crop Science Society of America and can be found at: https://dl.sciencesocieties.org/publications/cs Close

• 36. [Article] Yield and quality of cereals for winter silage production

  A field study was conducted in 1978 and 1979 at two locations near Corvallis, Oregon, to determine the silage yield and quality of 13 fallsown cereal varieties at two nitrogen fertilizer levels in the ...

  Citation × Citation Citation Abstract Copy Title: Yield and quality of cereals for winter silage production Author: Ben Ali, Mohamed Noureddine A field study was conducted in 1978 and 1979 at two locations near Corvallis, Oregon, to determine the silage yield and quality of 13 fallsown cereal varieties at two nitrogen fertilizer levels in the context of a corn-winter cemal double cropping production system. Data on the yield, crude protein (CP) content, acid and neutral detergent fiber (ADF and NDF) contents were collected on Adair, Casbon and FB 73130 barley (Hordeum vulgare L.) varieties, Amity, Cayuse and Grey winter oats (Avena Sativa L.), Abruzi and Kung rye (Secale cereale L.), S-72, Sel N-91 and VT 75-229 Triticale (Triticum X Secale) and Stephens and Yamhill wheat (Triticum Aestivum L.) varieties. The statistical analysis of the data gave the following results. Dry matter yields ranged on the average from a high of 8327 kg/ha to a low of 4631 ka/ha. Abruzi rye generally yielded the most dry matter. It was followed by Sel N-91 and VT 75-229 Triticales, Kung rye, S-72 Triticale and the wheat varieties. The barley and oats varieties were generally the lowest producers. Crude protein content was within the range of 6,5 to 10.1 percent of the dry matter. It was on the average highest for FB 73130 barley followed by Casbon barley, Stephens wheat, Adair barley, Yamhill wheat and the Triticale varieties. Acid detergent fiber ranged from 30.8 to 46.4 percent of dry matter. The oats varieties had the lowest ADF values, followed by Stephens and Yamhill wheats, FB 73130 and Adair barleys and VT 75-229 Triticale. The average neutral detergent fiber content for the 13 cereal varieties varied from a low of 50.3 to a high of 69.4 percent of D.M. The oats varieties were generally lowest followed by Stephens and Yamhill wheats, FB 73130 barley, VT 75-229 Triticale, Adair barley and Sel N-91 and S-72 Triticales. Covariance analysis indicated that a strong linear relationship existed between the yield and the quality components of the cereal varieties. When CP, ADF and NDF contents were adjusted for the same yield, it was found that the nitrogen fertilizer effect was no longer significant for either ADF or NDF. Title: Yield and quality of cereals for winter silage production Author: Ben Ali, Mohamed Noureddine A field study was conducted in 1978 and 1979 at two locations near Corvallis, Oregon, to determine the silage yield and quality of 13 fallsown cereal varieties at two nitrogen fertilizer levels in the context of a corn-winter cemal double cropping production system. Data on the yield, crude protein (CP) content, acid and neutral detergent fiber (ADF and NDF) contents were collected on Adair, Casbon and FB 73130 barley (Hordeum vulgare L.) varieties, Amity, Cayuse and Grey winter oats (Avena Sativa L.), Abruzi and Kung rye (Secale cereale L.), S-72, Sel N-91 and VT 75-229 Triticale (Triticum X Secale) and Stephens and Yamhill wheat (Triticum Aestivum L.) varieties. The statistical analysis of the data gave the following results. Dry matter yields ranged on the average from a high of 8327 kg/ha to a low of 4631 ka/ha. Abruzi rye generally yielded the most dry matter. It was followed by Sel N-91 and VT 75-229 Triticales, Kung rye, S-72 Triticale and the wheat varieties. The barley and oats varieties were generally the lowest producers. Crude protein content was within the range of 6,5 to 10.1 percent of the dry matter. It was on the average highest for FB 73130 barley followed by Casbon barley, Stephens wheat, Adair barley, Yamhill wheat and the Triticale varieties. Acid detergent fiber ranged from 30.8 to 46.4 percent of dry matter. The oats varieties had the lowest ADF values, followed by Stephens and Yamhill wheats, FB 73130 and Adair barleys and VT 75-229 Triticale. The average neutral detergent fiber content for the 13 cereal varieties varied from a low of 50.3 to a high of 69.4 percent of D.M. The oats varieties were generally lowest followed by Stephens and Yamhill wheats, FB 73130 barley, VT 75-229 Triticale, Adair barley and Sel N-91 and S-72 Triticales. Covariance analysis indicated that a strong linear relationship existed between the yield and the quality components of the cereal varieties. When CP, ADF and NDF contents were adjusted for the same yield, it was found that the nitrogen fertilizer effect was no longer significant for either ADF or NDF. Close

• 37. [Article] Estimating plant-available nitrogen release from cover crops

  Published November 2012. Reviewed October 2016. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog

  Citation × Citation Citation Abstract Copy Title: Estimating plant-available nitrogen release from cover crops Author: Andrews, N. (Nick), Oregon State University. Extension Service, Sullivan, Dan M. (Dan Matthew), 1954- Published November 2012. Reviewed October 2016. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Estimating plant-available nitrogen release from cover crops Author: Andrews, N. (Nick), Oregon State University. Extension Service, Sullivan, Dan M. (Dan Matthew), 1954- Published November 2012. Reviewed October 2016. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 38. [Article] Economic evaluation of different cropping patterns under irrigated agriculture : a multidisciplinary approach

  The purpose of this study is to determine the socioeconomic factors which influence the profitability and adoption of new cropping patterns, and to recommend suitable measures to enhance the crop diversification program ...

  Citation × Citation Citation Abstract Copy Title: Economic evaluation of different cropping patterns under irrigated agriculture : a multidisciplinary approach Author: Mahrouf, Abdul R. M. The purpose of this study is to determine the socioeconomic factors which influence the profitability and adoption of new cropping patterns, and to recommend suitable measures to enhance the crop diversification program in Mahaweli System B, Sri Lanka. The adoption of new cropping patterns is determined by a number of interrelated and mutually reinforcing factors. Hence, a multidisciplinary approach is used in this study to apprehend the different attributes of the new cropping patterns and farmers' decision making environment. The analytical methods include Marginal Cost-Benefit Analysis, Multivariate Analysis of Variance, Factor Analysis and Logit Probability Model. The results from the different techniques are generally in close agreement and complement each other. Results of the Marginal Cost- Benefit Analysis indicates that an increase in current crop yields and output prices may be necessary to increase the profitability of new cropping patterns to a recommendable level. Analysis of the farmers' beliefs suggests that adopters of the new cropping patterns have more positive beliefs towards the profitability and adoption of new cropping patterns when compared to nonadopters. Factor Analysis shows that there is a wide variation between the adopters and non-adopters, and also across the different locations with respect to farm-level variables. The analysis demonstrated that the information provided by 17 selected farm-level variables may be explained by four factors; namely, management factor, social factor, farm resource factor and farm stability factor. The variables highly loaded with the stability factor (number of years of residence, amount of loan obtained for farming, irrigation condition and percentage of rice produced allocated for consumption) are closely associated with the adoption rate. A logit probability model indicates that availability of farm loans significantly increases the probability of the adoption of new cropping patterns. The study results show that the crop yield, output prices, availability of farm loans and farmer beliefs, are the dominant factors which influence the adoption of new cropping patterns. Title: Economic evaluation of different cropping patterns under irrigated agriculture : a multidisciplinary approach Author: Mahrouf, Abdul R. M. The purpose of this study is to determine the socioeconomic factors which influence the profitability and adoption of new cropping patterns, and to recommend suitable measures to enhance the crop diversification program in Mahaweli System B, Sri Lanka. The adoption of new cropping patterns is determined by a number of interrelated and mutually reinforcing factors. Hence, a multidisciplinary approach is used in this study to apprehend the different attributes of the new cropping patterns and farmers' decision making environment. The analytical methods include Marginal Cost-Benefit Analysis, Multivariate Analysis of Variance, Factor Analysis and Logit Probability Model. The results from the different techniques are generally in close agreement and complement each other. Results of the Marginal Cost- Benefit Analysis indicates that an increase in current crop yields and output prices may be necessary to increase the profitability of new cropping patterns to a recommendable level. Analysis of the farmers' beliefs suggests that adopters of the new cropping patterns have more positive beliefs towards the profitability and adoption of new cropping patterns when compared to nonadopters. Factor Analysis shows that there is a wide variation between the adopters and non-adopters, and also across the different locations with respect to farm-level variables. The analysis demonstrated that the information provided by 17 selected farm-level variables may be explained by four factors; namely, management factor, social factor, farm resource factor and farm stability factor. The variables highly loaded with the stability factor (number of years of residence, amount of loan obtained for farming, irrigation condition and percentage of rice produced allocated for consumption) are closely associated with the adoption rate. A logit probability model indicates that availability of farm loans significantly increases the probability of the adoption of new cropping patterns. The study results show that the crop yield, output prices, availability of farm loans and farmer beliefs, are the dominant factors which influence the adoption of new cropping patterns. Close

• 39. [Article] Effect of several apple rootstocks on growth, yield components and leaf area estimates on "Starkspur Supreme Delicious" trees

  Growth, yield components and leaf area were evaluated on 'Starkspur Supreme Delicious' apple on nine rootstocks: MAC 24, EMLA 7, EMLA 26, OAR 1, MAC 9, 0.3, EMLA 9, M 9, and EMLA 27. Estimates of planting ...

  Citation × Citation Citation Abstract Copy Title: Effect of several apple rootstocks on growth, yield components and leaf area estimates on "Starkspur Supreme Delicious" trees Author: Siller-Cepeda, Jorge H. Growth, yield components and leaf area were evaluated on 'Starkspur Supreme Delicious' apple on nine rootstocks: MAC 24, EMLA 7, EMLA 26, OAR 1, MAC 9, 0.3, EMLA 9, M 9, and EMLA 27. Estimates of planting density based on growth, estimates of leaf area based on four independent variables and the relationships among yield components, fruit quality, growth and leaf area were investigated during 1985. Tree height, tree spread and trunk cross sectional area were highest for trees on MAC 24 followed for EMLA 7 while trees on EMLA 26, OAR 1, MAC 9, 0.3, EMLA 9 and M 9 were less in these values in descending order, with the most dwarfing on EMLA 27. Estimates of planting densities indicated higher densities with tree canopy spread than TCSA based on standard trees of the age except on EMLA 27. The densities for trees on MAC 24 and EMLA 7 were estimated 426 and 496 trees/ha. respectively, while for the rootstocks with intermediate size ranged from 700 to 1000 trees/ha. The highest density was for EMLA 27 with 1824 trees/ha. Flower cluster, fruit number, yield and leaf area were highest in the least size controlling rootstocks MAC 24 and EMLA 7, and in general these were a function of tree size. MAC 9 had the highest flowering density, crop density and yield efficiency followed by 0.3, EMLA 26 and EMLA 9. Potential yields based on the estimated planting density were also highest for MAC 9. Fruit on OAR 1 had greatest soluble solids, firmest at harvest, but were the smallest. Fruit on EMLA 7 which had the lowest soluble solids were largest. A negative correlation between flowering density and fruit set among the rootstocks was found. Crop density influenced fruit size and weight. Fruit on EMLA 7, MAC 24 and EMLA 9 were the largest but these trees had the lowest crop density. There was a high correlation of fruit number with yield indicating this was the main component of yield. The leaf-fruit ratio was negatively correlated with flowering density, crop density and yield efficiency and the ratio was lowest on the more efficient rootstocks MAC 9, 0.3 and M 9 while those of MAC 24 and EMLA 7 were highest. No differences were seen among the regression lines of leaf area and 4 independent variables obtained from trees on various rootstocks and within rootstock. Fresh weight was the best estimate of leaf area but because of greater speed and simplicity, branch cross sectional area was chosen to predict leaf area. Total leaf area per tree decreased from the least size controlling rootstocks to the most dwarfing rootstocks. Tree leaf area index ranged from 1.69 in MAC 24 to 0.87 in 0.3, but it did not always increase proportionately to tree size. Orchard leaf area index from estimated planting densities showed low values in all rootstocks but a slight increase with the tree size. This indicated that trees at the estimated densities are not intercepting the maximum quantity of light. Title: Effect of several apple rootstocks on growth, yield components and leaf area estimates on "Starkspur Supreme Delicious" trees Author: Siller-Cepeda, Jorge H. Growth, yield components and leaf area were evaluated on 'Starkspur Supreme Delicious' apple on nine rootstocks: MAC 24, EMLA 7, EMLA 26, OAR 1, MAC 9, 0.3, EMLA 9, M 9, and EMLA 27. Estimates of planting density based on growth, estimates of leaf area based on four independent variables and the relationships among yield components, fruit quality, growth and leaf area were investigated during 1985. Tree height, tree spread and trunk cross sectional area were highest for trees on MAC 24 followed for EMLA 7 while trees on EMLA 26, OAR 1, MAC 9, 0.3, EMLA 9 and M 9 were less in these values in descending order, with the most dwarfing on EMLA 27. Estimates of planting densities indicated higher densities with tree canopy spread than TCSA based on standard trees of the age except on EMLA 27. The densities for trees on MAC 24 and EMLA 7 were estimated 426 and 496 trees/ha. respectively, while for the rootstocks with intermediate size ranged from 700 to 1000 trees/ha. The highest density was for EMLA 27 with 1824 trees/ha. Flower cluster, fruit number, yield and leaf area were highest in the least size controlling rootstocks MAC 24 and EMLA 7, and in general these were a function of tree size. MAC 9 had the highest flowering density, crop density and yield efficiency followed by 0.3, EMLA 26 and EMLA 9. Potential yields based on the estimated planting density were also highest for MAC 9. Fruit on OAR 1 had greatest soluble solids, firmest at harvest, but were the smallest. Fruit on EMLA 7 which had the lowest soluble solids were largest. A negative correlation between flowering density and fruit set among the rootstocks was found. Crop density influenced fruit size and weight. Fruit on EMLA 7, MAC 24 and EMLA 9 were the largest but these trees had the lowest crop density. There was a high correlation of fruit number with yield indicating this was the main component of yield. The leaf-fruit ratio was negatively correlated with flowering density, crop density and yield efficiency and the ratio was lowest on the more efficient rootstocks MAC 9, 0.3 and M 9 while those of MAC 24 and EMLA 7 were highest. No differences were seen among the regression lines of leaf area and 4 independent variables obtained from trees on various rootstocks and within rootstock. Fresh weight was the best estimate of leaf area but because of greater speed and simplicity, branch cross sectional area was chosen to predict leaf area. Total leaf area per tree decreased from the least size controlling rootstocks to the most dwarfing rootstocks. Tree leaf area index ranged from 1.69 in MAC 24 to 0.87 in 0.3, but it did not always increase proportionately to tree size. Orchard leaf area index from estimated planting densities showed low values in all rootstocks but a slight increase with the tree size. This indicated that trees at the estimated densities are not intercepting the maximum quantity of light. Close

• 40. [Article] Response of wheat (Triticum aestivum L.) cultivars and downy brome (Bromus tectorum L.) to metribuzin and ethyl metribuzin

  Downy brome (Bromus tectorum. L.), a serious grass weed in eastern Oregon can be partially controlled in wheat by metribuzin [4-amino-6-tertbutyl- 3-(methylthio)-as triazin -5(4H)-one]. However, cultivars ...

  Citation × Citation Citation Abstract Copy Title: Response of wheat (Triticum aestivum L.) cultivars and downy brome (Bromus tectorum L.) to metribuzin and ethyl metribuzin Author: Munir, Muhammad Downy brome (Bromus tectorum. L.), a serious grass weed in eastern Oregon can be partially controlled in wheat by metribuzin [4-amino-6-tertbutyl- 3-(methylthio)-as triazin -5(4H)-one]. However, cultivars of many crops Lave been reported to differ in their level of tolerance to metribuzin. This lack of tolerance has led to the investigation of other compounds, such as the ethylthio analog of metribuzin [4-amino-6-tert-butyI-3-(ethylthio)-as-triazin- 5(4H)-on], for selective control of downy brome in wheat. Greenhouse and growth chamber experiments on wheat, growing in soil or nutrient solution showed that: 1) GR50 values for Stephens, Hill 81, Yanahill, and Malcolm in soil were 0.41, 0.23, 0.25, and 0.44 kg/ha, respectively, for metribuzin and 1.89, 1.29, 1.37, and 1.97 kg/ha, respectively, for ethyl metribuzin; 2) GR50 values for these cultivars in nutrient solution were 3.26, 1.17, 1.32, and 3.87 uM, respectively, for metribuzin and 12.69, 7.20, 7.19, and 13.41 uM, respectively, for ethyl metribuzin; 3) Uptake of both herbicides.; by wheat was through the roots; 4) Cultivars did not show any differences in herbicide absorption from the nutrient solution. Therefore, differences in varietal tolerance may be are due to biochemical or physiological reasons, but are not due to differences in herbicide uptake. Increased growth at lower concentrations of these herbicides was observed in all cultivars studied. Metribuzin was five times more active than ethyl metribuzin. Both of these herbicides can be applied as an early postemergence treatment at the 3 leaf stage of wheat for effective control of downy brome. Yield components of the four cultivars were measured in response to metribuzin and ethyl metribuzin at two ecologically different sites. The susceptible cultivars (Hill 81 and Yamhill) showed greater injury in the lighter soils with high pH and lower organic matter content. Visual estimates of crop injury were generally higher than the actual reduction in final yield. Crop injury ratings up to 25% generally did not show a significant reduction in final grain yield. A positive correlation between protein content and concentration of these herbicides was noted. A study on the joint action of these two herbicides in the field and greenhouse showed that the combination of the two, increased the control of downy brome at lower rates. Their combined action was studied by using Colby's method and isobole method of Tammes. The reaction was calculated as additive. Downy brome was 8, 5, 5, and 9 times more sensitive to metribuzin and 6, 4, 4, and 6, times more sensitive to ethyl metribuzin than were the cultivars Stephens, Hill 81, Yamhill, and Malcolm, respectively. The use of these two herbicides to control downy brome in the cultivars Hill 81 and Yamhill should be avoided unless careful attention is given to soil properties and environmental conditions. Title: Response of wheat (Triticum aestivum L.) cultivars and downy brome (Bromus tectorum L.) to metribuzin and ethyl metribuzin Author: Munir, Muhammad Downy brome (Bromus tectorum. L.), a serious grass weed in eastern Oregon can be partially controlled in wheat by metribuzin [4-amino-6-tertbutyl- 3-(methylthio)-as triazin -5(4H)-one]. However, cultivars of many crops Lave been reported to differ in their level of tolerance to metribuzin. This lack of tolerance has led to the investigation of other compounds, such as the ethylthio analog of metribuzin [4-amino-6-tert-butyI-3-(ethylthio)-as-triazin- 5(4H)-on], for selective control of downy brome in wheat. Greenhouse and growth chamber experiments on wheat, growing in soil or nutrient solution showed that: 1) GR50 values for Stephens, Hill 81, Yanahill, and Malcolm in soil were 0.41, 0.23, 0.25, and 0.44 kg/ha, respectively, for metribuzin and 1.89, 1.29, 1.37, and 1.97 kg/ha, respectively, for ethyl metribuzin; 2) GR50 values for these cultivars in nutrient solution were 3.26, 1.17, 1.32, and 3.87 uM, respectively, for metribuzin and 12.69, 7.20, 7.19, and 13.41 uM, respectively, for ethyl metribuzin; 3) Uptake of both herbicides.; by wheat was through the roots; 4) Cultivars did not show any differences in herbicide absorption from the nutrient solution. Therefore, differences in varietal tolerance may be are due to biochemical or physiological reasons, but are not due to differences in herbicide uptake. Increased growth at lower concentrations of these herbicides was observed in all cultivars studied. Metribuzin was five times more active than ethyl metribuzin. Both of these herbicides can be applied as an early postemergence treatment at the 3 leaf stage of wheat for effective control of downy brome. Yield components of the four cultivars were measured in response to metribuzin and ethyl metribuzin at two ecologically different sites. The susceptible cultivars (Hill 81 and Yamhill) showed greater injury in the lighter soils with high pH and lower organic matter content. Visual estimates of crop injury were generally higher than the actual reduction in final yield. Crop injury ratings up to 25% generally did not show a significant reduction in final grain yield. A positive correlation between protein content and concentration of these herbicides was noted. A study on the joint action of these two herbicides in the field and greenhouse showed that the combination of the two, increased the control of downy brome at lower rates. Their combined action was studied by using Colby's method and isobole method of Tammes. The reaction was calculated as additive. Downy brome was 8, 5, 5, and 9 times more sensitive to metribuzin and 6, 4, 4, and 6, times more sensitive to ethyl metribuzin than were the cultivars Stephens, Hill 81, Yamhill, and Malcolm, respectively. The use of these two herbicides to control downy brome in the cultivars Hill 81 and Yamhill should be avoided unless careful attention is given to soil properties and environmental conditions. Close