长期轮作对黄土高原旱地小麦籽粒蛋白质营养品质的影响

在长期定位试验条件下，研究了黄土高原旱地粮草（小麦-红豆草）、粮豆（小麦-豌豆）和粮饲（小麦-玉米）3种典型轮作制度对小麦籽粒蛋白质营养品质的影响.结果表明： 轮作制度及茬口年限可对黄土高原旱地小麦籽粒蛋白质营养品质产生不同程度的影响.与连作小麦相比，实行小麦-红豆草轮作后，小麦籽粒蛋白质营养品质较稳定，且其籽粒蛋白质必需氨基酸含量、氨基酸评分、氨基酸比值系数、化学评分和氨基酸指数均较高，可作为黄土高原生产优质蛋白小麦的轮作制度；小麦与豌豆进行轮作，豌豆茬后1年小麦籽粒蛋白质营养品质较高，但豌豆茬后2年小麦籽粒蛋白质必需氨基酸含量较低，且多种必需氨基酸评分和化学评分低于连作小麦，必需氨基酸指数比连作小麦低12.2%，营养品质较低；虽然粮饲轮作小麦籽粒蛋白质营养品质较稳定，但其粗蛋白、必需氨基酸含量及氨基酸平衡程度均低于连作小麦.

Effects of long term rotation on the nutritional quality of wheat grain protein on dryland of Loess Plateau,Northwest China.

A long-term experiment was conducted on the dryland of Loess Plateau to study the effects of three typical rotation systems, including wheat-sainfoin rotation, wheat pea rotation, and wheat-maize rotation, on the nutritional quality of wheat grain protein. Rotation system and the cropping years of rotated plants affected the nutritional quality of wheat grain protein in varying degrees. As compared with continuous wheat cropping, wheat-sainfoin rotation made the nutritional quality of wheat grain protein relatively stable, and the essential amino acid content, amino acid score, amino acid ratio coefficient, chemical score, and amino acid index of the protein all relatively high, being able to be adopted as a cropping system to product high quality protein wheat in Loess Plateau. Under wheat-pea rotation, the nutritional quality of wheat grain protein after 1 year pea cropping was relatively high, but the essential amino acid content of wheat grain protein after 2-year- pea cropping was relatively low, and several essential amino acid scores and chemical score of the grain protein were lower than those under continuous wheat cropping. Furthermore, the essential amino acid index was 12.2% lower than that under continuous wheat cropping. Therefore, wheat-pea rotation showed a relatively low nutritional quality of wheat grain protein. Under wheat-maize rotation, the nutritional quality of wheat grain protein was also relatively stable, but the crude protein and essential amino acid contents and amino acid balance level were lower than those under continuous wheat cropping.