旱作条件下施肥对老芒麦和冰草种子产量及构成的影响I-氮、磷、钾对牧草种子产量及构成的影响

对老芒麦和诺丹冰草种子生产田的施肥试验表明 ,N肥、P肥单施及 N、P和 N、P、K混施可使老芒麦实际种子产量及各产量构成因子指标有显著提高 ,但 N、P、K及 N、P混施效果优于 N肥、P肥单施。 N肥、P肥、K肥单施对诺丹冰草种子增产效应不明显 ,但 N、P、K混施对提高诺丹冰草种子产量及各产量构成因子指标有显著效应。在老芒麦种子生产中每公顷施用 1 2 0 kg的 N和 90 kg的 P可获得较高的产量 ;而在诺丹冰草种子生产中每公顷施用1 2 0 kg的 N和 60 kg的 P可获得较高的产量。施肥试验的结果亦提示 ,在旱作条件下 ,干旱年份施肥可能并不是一种较经济的提高产量的措施

Effects of Fertilizer Applications on Seed Production and Seed Yield Components of Grasses in Rain-Fed Cultivation Practice I

The effects of nitrogen, phosphorus and potassium on seed yields of Elymus sibiricus and Agropyron desertorum cv.nordan were tested. The results showed that nitrogen or phosphorus both could increase the seed yield of E. Sibiricus, more than 40% of the seed yield increase was obtained when nitrogen, phosphorus and potassium were applied in combination. Application of nitrogen, phosphorus or potassium separately showed no obvious effects on the seed yield of A. desertorum cv.nordan. When applying them in combination, 30% of the seed yield increase were obtained. The suitable amounts of fertilizers for E. Sibiricus were of 120kg/ha of nitrogen and 90kg/ha of phosphorus, and those for A. desertorum cv.nordan were of 120kg/ha of nitrogen and 60kg/ha of phosphorus. The results of the tests also hinted that in the year of lower precipitation, fertilizer application in dry land conditions may not be an economical managerial strategy to obtain higher seed yields.