Author
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Honeycutt, Charles |
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Submitted to: Plant Foods for Human Nutrition
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/26/1998 Publication Date: N/A Citation: N/A Interpretive Summary: The impacts of nitrogen (N) fertilization on potato protein yield and nutritional quality are well documented but of little benefit to growers with limited access to fertilizer or capital (e.g. in lesser developed countries) or for growers choosing not to apply N fertilizer (e.g. organic production). This study was conducted to evaluate the extent that total protein yield in potato can be influenced by crop rotation with no N fertilizer. A field study was conducted in which potato followed previous crops of alfalfa, hairy vetch, white lupin, oat, and potato. Tuber protein yield following alfalfa with no N fertilizer was about 45 lbs./acre greater than when following potato or oat in one study year. In another year, tuber protein yield was greatest following vetch, achieving 133 lbs./acre with no N fertilizer. These results were directly linked to the N contribution of rotation crop residues and were reflected in the plant-available N levels measured in soil. Particular crops (e.g. alfalfa and vetch) grown in rotation with potato can make significant contributions to the total protein harvested in tubers. Technical Abstract: The impacts of nitrogen (N) fertilization on potato protein yield and nutritional quality are well documented but of little benifit to groweres with limited access to fertilizer or capital (e.g. in lesser developed countries) or for growers choosing not to apply fertilizer (e.g. organic production). This study was conducted to evaluate the extent that crude protien yield in potato can be influenced by crop rotation. Potato was grown following previous crops of alfalfa, hairy vetch, white lupin, oat, and potato. Tuber protien yield following alfalfa was about 50 kg ha-1 greater than when following potato or oat in one study year. In another year , tuber protien yield was greatest following each vetch, achieving 149 kg protien ha-1 with no N fertilizer. These results were directly linked to the N contribution of rotation crop residues and were reflected in the plant-available N measured in soil. Applying one-half the recommended rate of N fetilizer resulted in protein yields comparable to a well-fertilized potato-potato rotation in a dry year, but not in a year with more favorable precipitation. Rotation crops can significantly contribute to the total protein harvested in tubers. This informationmay be useful in combating protein-calorie malnutrition and in developing organic production guidelines for optimal nutritional quailty. |
