长期施用有机肥对黑土土壤肥力和玉米产量的影响

Effects of long-term manure application on black soil fertility and maize yield

我国有机肥资源丰富并且有施用有机肥培肥土壤的传统,为了探讨有机肥的培肥效果及玉米产量的响应,于2003年在东北黑土区中部建立了有机肥还田定位试验,设置了无肥(CK)、化肥(NPK)和有机肥(M)3个处理开展研究,有机肥的施用量为22500 kg·hm^-2。研究结果表明,试验期间CK处理玉米产量均显著低于NPK和M处理(P<0.05),2003-2015年间NPK处理玉米产量较M处理显著提高了10.7%~29.4%(P<0.05),有机培肥13 a以后M处理玉米产量与NPK处理没有显著差异(2018年除外)(P>0.05),表明连续有机培肥后的土壤有实现有机肥替代化肥的能力。与初始土壤相比,在0~20 cm和20~40 cm土层,M处理土壤有机碳、全氮、全磷、碱解氮、速效磷和速效钾含量分别显著增加了48.8%~315%和12.4%~147%(P<0.05),NPK处理仅显著增加了速效磷的含量,CK处理有机碳、全氮和碱解氮含量分别显著下降了13.8%~24.0%和17.0%~27.0%。M处理显著降低了0~20 cm和20~40 cm土层的土壤容重,显著提高了0~20 cm土层的通气孔隙度。有机肥的长期施用能够提高0~40 cm土层土壤肥力,改善土壤结构,对有机肥替代化肥促进作物产量的稳定和提高的主要原因。

China is rich in manure resource,and farmers are used to applying manures to cultivate the soil in history.A field experiment was established in 2003 in the black soil region of northeast China,in order to investigate the effects of manure application on maize yield and soil fertility.No fertilizer(CK),chemical fertilizer(NPK)and manure(M)were included in this experiment with four replicates and randomized block design.The manure rate of 22500 kg·hm^-2 was applied in M treatment annually.Maize yield under CK treatment was significantly lower than NPK and M treatments during experimental years(P<0.05).Maize yield of NPK treatment was 10.7%-29.4%higher than M treatment from 2003 to 2015(P<0.05),and was the same as M treatment after 13 experimental years.Long-term manure application has the potential in replacing chemical fertilizer for black soil fertility.Compared with initial soil,soil organic carbon(SOC),total nitrogen(TN),total phosphorus(TP),available nitrogen(AN),available phosphorus(AP)and available potassium(AK)contents were significantly increased by 48.8%-315%and 12.4%-147%under M treatment for 0-20 cm and 20-40 cm soil layers,respectively.NPK treatment significantly increased AP content.The contents of SOC,TN and AN under CK treatment were significantly decreased by 13.8%-24.0%and 17.0%-27.0%for 0-20 cm and 20-40 cm soil layers,respectively.Meanwhile,M treatment significantly decreased soil bulk density within 0-20 cm and 20-40 cm soil layers and significantly increased aeration porosity within 0-20 cm soil layer.Long-term manure application increases soil fertility and improves soil structure within 0-40 cm soil layer,which are the main reason for the enhancement and stability of crop yield by manure replacing chemical fertilizer.