磷肥残效及农业系统养分循环再利用中长期试验

在辽宁西部褐土上进行的一12年中长期田间试验结果表明:每年施用小剂量磷（P14.4kghm-2）和每6年1次大剂量磷（P86.4kghm-2）两种施磷方式的作物增产效果相似而以前者略优，两种施磷方式的磷肥利用率12年平均分别为0.38和0.36，表明磷肥在该土壤上有着极持久的残效。在施用氮磷肥基础上，每年以80％的收获籽实和2／3的秸杆喂猪、垫圈，猪圈肥循环回田，11年平均每公顷可增产粮食1吨，增产率17％。经连续施用12年循环回田猪圈肥后土壤的供氮力显著提高，年供氮量180～200kg（N），玉米产量每公顷接近9吨，当季施用氮肥几无增产作用。

A LONO-TERM FIELD TRIAL ON RESIDUAL EFFECT OF PHOSPHORUS AND ON THE USE OF RECYCLED NUTRIENTS IN A FARMING SYSTEM

Results from a twelve years field experiment on a calsic cinnamon soil in west Liaoning China indicated that the crop yields from the treatments with low rate (14. 4 kg.hm^-2) of phosphorus every year and with high rate (86. 4 kg· hm^-2) of phosphorus every six years were very similar but the former gave a little higher yields. The average recoveries of phosphorus of both treatments in twelve years were 0. 38 and 0. 36 respectively impling the significant residual effect of phosphorus on this soil. Based on the use of nitrogen and phosphorus fertilizer, the recycled pig manure, made by 80% of the grain from the treatrient to feed a pig and 2/3 of the stalk used as bedding material. could increase crop yields by 1 t.hm^-2 or 17% increase rate on average. After twelve years of appling recycled pig manure annually, the nitrogen suppling ability of the soil reached as high as 180-200 kg(N) per hectare per year, the yield of maize reached about 9 t·hm^-2without using nitrogen fertilizer.