培肥措施对侵蚀坡耕地春玉米产量与土壤养分的影响

摘要

Pointed at the problems of serious soil nutrients losses and low corps yield in slope farmland in the South-ern Mountain Region of Ningxia ,different degree of soil erosion was simulated by removing topsoil of 0 cm ,10 cm ,and 20 cm ,the purpose was to investigate the effect of four fertilization methods of single application of chemical fertilizers (NP ) ,combined application of organic-inorganic fertilizers (M+NP ) ,single application of organic manure (M ) ,and no fertilizers (CK) on spring maize yield ,soil organic matter ,and soil available N ,P ,K contents in erosion of slope farmland ,thereby proposed the fertilization model for improving crop yield and soil fertility in the erosion of slope farm-land .The results indicated that:Relative to the treatment CK ,the ear length ,row numbers per ear ,grain numbers per ear ,and 100 grain weight of spring maize were total increased by the treatments M and M+NP for different erosion de-gree of slope farmland ,and achieved the purpose of increasing crop yield .Both yield and yield components of spring maize were significantly decreased with the degree of soil erosion continuing to worsen in slope farmland .Relative to re-moving topsoil of 0 cm ,the yields of spring maize were significantly decreased by 26 .4% and 38 .5% ,respectively for the treatment removing topsoil of 10 cm and 20 cm .Under the same degree of soil erosion conditions ,the fertilization measures could significantly increase soil available N ,P ,K contents in 0~20 cm ,but there was no significant effect on soil organic matter content .However ,the average contents of soil organic matter and soil available N ,P ,K nutrients were assumed decreasing trend with the degree of soil erosion continuing to worsen in slope farmland .After application of organic manure or combined application of organic-inorganic fertilizers ,the proportion of sandy in soil was decreased , and clay content in soil was increased .So the soil physical structure can be effectively improved .%针对宁南山区坡耕地土壤养分流失严重和作物产量较低的问题，通过剥离表层土壤0、10 cm和20 cm模拟不同侵蚀程度，研究单施化肥（NP ）、有机无机配施（M＋NP ）和单施有机肥（M ）、不施肥（CK ）4个培肥措施对春玉米产量、耕层土壤有机质、碱解氮、土壤有效磷和土壤速效钾含量的影响，从而提出侵蚀坡耕地增产和培肥效果俱佳的施肥模式。结果表明，相对于CK处理，M和M＋NP处理均能改善不同侵蚀程度下坡耕地春玉米的穗长、穗行数、穗粒数和百粒重等农学性状，达到增产目的。随着坡耕地土壤侵蚀程度的增加，春玉米的各产量构成因素和产量都出现显著降低趋势。相对于0 cm土层，表土剥离10 cm和20 cm侵蚀处理下春玉米分别显著减产了26．4％和38．5％。在同等侵蚀条件下，施肥措施能显著增加0～20 cm土壤碱解氮、有效磷和速效钾含量，而对土壤有机质含量影响不大；但随着土壤侵蚀程度的增加，土壤有机质和速效氮、磷、钾养分平均含量呈降低趋势。施用有机肥或有机无机配施还能降低土壤砂粒比例，提高粘粒含量，有效地改善土壤物理结构。