有机肥替代氮肥对银北灌区盐化灌淤土理化性质及玉米生长的影响

Effects of Partial Substitution of Nitrogen Fertilizer with Organic Fertilizer on Soil Physicochemical Properties and Maizegrowth in Salinized Irrigation and Silting Soilsof Northern Ningxia

次生盐渍化已成为宁夏银北灌区灌淤土壤退化的主要形式,制约着宁夏农业持续高质量发展。为了给宁夏地区盐化灌淤土的施肥管理及提高作物产量提供科学依据,以银北灌区典型盐化灌淤土为研究对象、玉米品种先玉335为指示品种,研究了不同施肥水平对盐化灌淤土土壤理化性质及玉米生长的影响。结果表明,各施肥处理均能有效地增加盐化灌淤土的速效养分含量,进而优化玉米产量构成要素,提高玉米产量。各施肥处理除常规施肥处理(施N 375.0 kg/hm^(2)、P_(2)O_(5)100.0 kg/hm^(2)、K_(2)O 100.0 kg/hm^(2))的玉米总根长、根表面积最高外,有机肥替代常规施肥量50%氮肥(施N 187.5 kg/hm^(2)、P_(2)O_(5)100.0 kg/hm^(2)、K_(2)O 100.0 kg/hm^(2)、有机肥7.3 t/hm^(2))处理的土壤理化性质及玉米生长指标最高。与对照不施肥相比,该处理下土壤有机质、速效氮、速效磷、速效钾分别增加了34.5%、25.9%、120.5%、23.7%,玉米穗长、穗粗、穗粒数、产量分别增加了40.5%、15.2%、80.5%、104.8%,秃尖长降低了78.0%;与常规施肥处理相比,该处理下土壤有机质、速效氮、速效磷、速效钾分别增加了36.5%、21.4%、13.7%、8.6%,玉米穗长、穗粗、穗粒数、产量分别增加了0.6%、1.9%、5.3%、3.1%,秃尖长降低了57.7%。综合分析,不同施肥水平均可改善盐化灌淤土理化性质进而提升玉米产量,且以有机肥替代部分氮肥施用的处理效果较好,其中以有机肥替代常规施肥量50%氮肥的施肥水平效果最好。

Secondary salinization has become the main form of soil degradation in anthropogenic alluvial soils in theirrigation areas of Northern Yinchuan,which restricts the sustained high-quality development of agriculture in Ningxia.Taking the typical saline irrigation and silting soils in Ningxia as the research object and using Xianyu 335 as the indication variety,this paper analyzed the effects of different fertilizations on soil physical and chemical properties and maize growth,so as to provide a theoretical basis for fertilization management for saline irrigation and silting soil and improve crop yields in this region.The results showed that fertilization could effectively increase the contents of available nutrients in saline irrigated and silted soil,and therefore,increase maize yield and its constituent elements.In all fertilization treatments,all the soilphy sicochemical properties and maize growth parameters peaked under the treatment of 50% substitution of nitrogen fertilizer with organic fertilizer(N at 187.5 kg/ha,P_(2)O_(5) at 100.0kg/ha,K_(2)O at 100.0 kg/ha and organic fertilizer at 7.3 t/ha)in addition to the peak of root length androot surface are aunder conventional fertilization treatment(N at 375.0 kg/ha,P_(2)O_(5) at 100.0 kg/ha and K_(2)O at 100.0 kg/ha).When compared with nofertilization,contents of soil organic matter,available nitrogen,available phosphorus and available potassium under 50%substitution treatment were increased by 34.5%,25.9%,120.5% and 23.7%,respectively,whereas the ear length,ear diameter,number of grains per ear and yield of maize were increased by 40.5%,15.2%,80.5% and 104.8%,respectively,and the bald tip length was decreased by 78%.Compared with the conventional fertilization treatment,contents of soil organic matter,available nitrogen,available phosphorus and available potassium under 50%substitution treatment were increased by 36.5%,21.4%,13.7% and 8.6%,respectively,whereasthe ear length,ear diameter,number of grains per ear and yield of maize were increased by 0.6%,1.9%,5.3%and 3.1%,respectively,and the bald tip length was decreased by 57.7%.Comprehensive analysis showed thatdifferent fertilizations could improve the physical and chemical properties of saline irrigation and silting soil and then increase the yield of maize,and the effect of 50% substitution of nitrogen fertilizer with organic fertilizer was the most significant.