高寒半干旱区油菜与豆科牧草混播草地施肥效应

油菜与豆科牧草混播草地施肥效应表明，氮磷合理配施促进土壤水分消耗，干草、植物量和施肥产投比显著提高。坡梁地最高植物产量施肥量Ｎ为７８．０６ｋｇ／ｈｍ２，Ｐ２Ｏ５为６１．１５ｋｇ／ｈｍ２，最高干草产量施肥量Ｎ为７６．６５ｋｇ／ｈｍ２，Ｐ２Ｏ５为５７．２９ｋｇ／ｈｍ２，增产效果Ｎ＞Ｐ２Ｏ５；旱滩地最高植物产量施肥量Ｎ为５８．３３ｋｇ／ｈｍ２，Ｐ２Ｏ５为５５．６８ｋｇ／ｈｍ２，最高干草产量施肥量Ｎ为５３．６０ｋｇ／ｈｍ２，Ｐ２Ｏ５为５９．１１ｋｇ／ｈｍ２，增产效果Ｐ２Ｏ５＞Ｎ；且氮磷具有明显的正交互效应。氮磷合理配施还显著提高了水分利用效率，坡梁地和旱滩地分别提高３．０５和２．６７ｋｇ／（ｍｍ．ｈｍ２）。

Effect of Fertilizer Application on Rape Leguminous Pasture in Cold Semi Arid Region of High Elevation

This trial of fertilizer application to mixed rape leguminous pastures was carried out in Zhangbei county of Hebei province. It was shown that the maximal plant biomass on mountain slopes was achieved at the application norm: N 78.06 kg/ha and P 2O 5 61.15 kg/ha, while the maximal hay yield was obtained at the norm: N 76.65 kg/ha plus P 2O 5 57.29 kg/ha. In both cases the effect of N in increasing production was more obvious than P. On flat dry lands, on the other hand, the maximal biomass and hay yield were produced at the application norms of N 58.33 kg/ha plus P 2O 5 55.68 kg/ha and N 53.60 kg/ha plus P 2O 5 59.11 kg/ha, respectively, with P having more significant effect on production than N. The above combinations of N and P also showed significant effect on the utilisation efficiency of soil moisture, increasing biomass by 3.05 kg/mm.ha on slopes and 2.67 kg/mm.ha on flat dry lands.