一年两作长期施用氮磷钾的肥效及其对土壤肥力的影响

The Efficiency of NPK Long-term Application in Double Cropping System and the Effect on Soil Fertility

本文研究了河北省中上等肥力褐土在一年两作和施用与不施用有机肥料情况下,长期施用氮磷钾化肥的肥效和对土壤养分状况的影响.10年田间试验和2年盆栽试验结果表明:氮肥的增产作用明显;在施用有机肥条件下,一般年份磷钾肥效果不明显,但在冬春严寒的年份,磷肥也有明显增产效果.不施有机肥时,小麦施用磷肥效果明显;氮磷肥配合施用效果最好.在本试验条件下,施用氮、磷、钾肥对土壤有机质和氮素含量影响很小,土壤磷钾含量则随施用磷钾肥而明显变化.在施有机肥的条件下,年施氮15公斤/亩,P_2O_5 8公斤/亩,K_2O 18公斤/亩,土壤氮、磷、钾有盈余;不施有机肥时,施用同等量的化肥,则土壤氮、磷、钾均有亏缺.

Under conditioas of applying and without applying organic manure in the fields with cinnamon soil of medium-high fertility and with double cropping system, the efficiency of long-term application of NPK and their effect on soil nutrients were studied in Hebei province 10 year field experiments and 2 year pot tests showed that N fertilizer had a significant yield-increasing effect : Under normal weather conditions P and K fertilizers did not show obvious effect when caghnic manure was applied, but P would give a significant effect in the years when the weather was frigid in the winter and spring. After stopping applying organic manure, application of P fertilizer showed a significant effect on the winter wheat, and NP combination would be the best application form. In this experiment the effect of combined application of NPK fertilizers on organic matter in soil and nitrogen contents was small. P K contents in the soil changed with the variation in applied amount of P K. On the basis of organic manure, N 15kg mu,P2O5 8 kg mu,K2O 18kg mu were applied on the soil every year, the NPK contents in soil showed surplus. Under conditions of applying the chemical fertilizers in aforementioned amount but without having organic manure, N P K in the soil were lacking.