生物炭与氮肥配比对土壤微生物特性和红枣产量的影响

The Combination of Biochar Addition and Nitrogen Fertilizer Application Affects Soil Microbial Community and Functions and Jujube Yield

【目的】为枣区高效合理施肥、资源优化提供科学依据。【方法】以扁核酸红枣为研究对象,进行了以生物炭用量10、20和30 t/hm^23个水平,氮素用量300和400 kg/hm^22个水平的连续2 a(2017-2018年)田间试验,以不施生物炭和氮肥为对照(CK),分析了生物炭与氮肥不同配比对土壤微生物性质及红枣产量的影响。【结果】与CK相比,生物炭与氮肥配合施用显著提高了土壤过氧化氢酶的活性(11.5%~93.9%);脲酶和蔗糖酶的活性分别较CK显著提高8.1%~71.4%和2.1%~42.7%;其中以B30N400处理的土壤过氧化氢酶和脲酶活性最高,B30N300处理的土壤蔗糖酶活性最高。土壤细菌、放线菌和真菌数量总体表现出随生物炭和氮肥用量的增加而增加的趋势,与CK相比,三者的增幅分别为25.4%~254.1%、49.5%~97.5%和7.3%~54.1%。生物炭和氮肥的施入,不同程度上提高了扁核酸红枣的产量,其中以B30N300处理的扁核酸红枣年平均产量最高,为22052.73 kg/hm^2,较CK显著提高28.5%。【结论】30 t/hm^2的生物炭施用量、300 kg/hm^2的氮肥用量为此地区的适宜施用量。

【Background】Intensive cultivation including excessive application of agrochemicals is widely used by framers in north China as an insurance to achieve high yield.While nitrogen fertiliser is important to improve crop yield,its overuse in China has resulted in not only resource waste but also environmental contamination such as soil acidification and compaction,as well as groundwater pollution.Therefore,it is imperative to develop sustainable and environmentally friendly agronomical managements to improve soil quality while in the meantime reduce agrochemical application so as to ameliorate environmental pollution.Amending soil with biochar has proven able to improve soil quality due to its specific physicochemical properties,but how biochar addition and nitrogen application combine to alter soil fertility remains elusive.【Objective】The object of this study is to evaluate the combined impact of biochar amendment and nitrogen fertilizer application at different ratios on soil microbial community and activities in a jujube yield in the north China plain.【Method】The field experiment was conducted in non-polluted jujube production base in Neihuang county,Henan province in 2017 to 2018.It consisted of seven treatments:CK(no fertilizer and biochar amendment),three levels of biochar amendment(10,20 and 30 t/hm^2)and two levels of nitrogen fertilization(300 and 400 kg/hm^2).In each treatment,we measured soil enzymatic activities and microbial community.【Results】①Compared with CK,applying biochar and nitrogen fertilizer significantly improved the activities of catalase,urease and invertase in soil.The activities of catalase and urease peaked in B30+N400,up by 93.9%and 71.4%respectively over the CK.The activity of invertase peaked in B30+N300,increasing by 42.7%over the CK.②Soil microbial communities increased with biochar and nitrogen fertilizer application,with the numbers of bacteria,fungi and actinomycetes increasing by 25.4%~254.1%,49.5%~97.5%and 7.3%~54.1%,respectively,compared with CK.③Application of biochar and nitrogen fertilizer increased jujube yield,with the highest yield 22052.73 kg/hm^2 achieved in B30+N300,up 28.5%over the CK【Conclusion】Applying 30 t/hm^2 of biochar and 300 kg/hm^2 of nitrogen fertilizer appears to be optimal to maximize yield and enhance soil enzymatic activities.