生物质炭与有机物料配施的土壤培肥效果及对玉米生长的影响

生物质炭作为一种多功能的土壤培肥材料被广泛应用,但其与传统有机物料的对比及配施研究还比较少。通过盆栽试验,研究了生物质炭与秸秆、发酵鸡粪单施及配施对壤质潮土和砂土养分含量、酶活性及玉米生长的影响,并采用主成分分析方法对3种有机物料的培肥效果进行综合评价。试验设6个处理,分别为不添加有机物料(CK)、添加生物质炭(BC)、小麦秸秆(WS)、发酵鸡粪(CM)、秸秆和生物质炭(WS+BC)、鸡粪和生物质炭(CM+BC)。研究结果表明,各处理均增加了砂土玉米生物量和株高,3种有机物料的提升幅度排序为:鸡粪生物质炭秸秆,鸡粪还可增加壤质潮土玉米生物量和株高。添加生物质炭和有机物料还可提高土壤有机质含量,其中生物质炭的提升幅度最大。此外,3种有机物料对土壤养分和酶活性的影响各异,单施鸡粪分别增加壤质潮土和砂土的碱解氮22.08%和26.67%,速效磷91.92%和53.65%,脲酶活性40.54%和36.94%;单施生物质炭分别增加壤质潮土和砂土速效磷83.52%和89.91%,速效钾79.38%和127.02%,过氧化氢酶活性3.41%和11.22%,却降低了土壤碱解氮含量,且与鸡粪配施后会抑制鸡粪中氮的有效性;单施秸秆分别增加壤质潮土和砂土速效钾49.48%和63.02%,β-葡糖苷酶活性51.86%和59.09%;生物质炭与鸡粪或秸秆配施可以更均衡地提升土壤肥力。通过主成分分析和相关分析发现,玉米生物量和株高与土壤氮、磷供应正变化的第2主成分(PC2)得分呈极显著正相关关系。因此,3种有机物料中,鸡粪对土壤氮、磷含量及相关酶活性影响最大;秸秆对土壤钾以及纤维素分解相关酶影响较大,而生物质炭对土壤肥力的提升作用更均衡,且土壤肥力综合得分最高。秸秆或鸡粪配施生物质炭可以更全面地提高土壤肥力。

Effects of combined biochar and organic matter on soil fertility and maize growth

As a new functional material, biochar can increase soil carbon pool, improve soil quality and increase crop yield because of its particulate physical and chemical properties and is thus widely used in agriculture. However, studies on the comparison between biochar and traditional organic matter and their combined application are relatively rare. Thus a pot ex-periment was conducted to study the effect of the separate application of biochar, straw and chicken manure or their combined application on nutrient status, enzyme activity of soil and maize growth in fluvo-aquic loamy and sandy soils. Principal com-ponent analysis and simple correlation analysis were also used to synthetically evaluate the effects of different treatments and to determine the main driving factors of maize growth. All in all, a total of six treatments were conducted: control (CK), bio-char (BC), wheat straw (WS), chicken manure (CM), wheat straw plus biochar (WS+BC) and chicken manure plus biochar (CM+BC). The results showed that all treatments increased maize biomass and height in sandy soil, the order of treatments in terms of maize growth was CM+BC = CM > WS+BC, BC > WS > CK, and manure could also increase maize biomass and height in fluvo-aquic loamy soil. Biochar and organic matter increased soil organic matter content, with the former particularly inducing a sharp increase. Different treatments showed different effects on soil nutrients and enzyme activities in both flu-vo-aquic loamy and sandy soils. Chicken manure respectively increased soil available N by 22.08％ and 26.67％, available P by 91.92％ and 53.65％, and urease activity by 40.54％ and 36.94％ in fluvo-aquic loamy and sandy soils. Biochar respectively increased soil available P by 83.52％ and 89.91％, soil available K by 79.38％ and 127.02％, and soil catalase activity by 3.41％ and 11.22％ in the two soil types. Wheat straw respectively increased soil available K by 49.48％ and 63.02％, soilβ-glucoside enzyme activity by 51.86％ and 59.09％ in both fluvo-aquic loamy and sandy soils. Overall, combined application of biochar and manure or straw complemented each other and thereby improved more comprehensively soil fertility. Principal component analy-sis and correlation analysis suggested that maize biomass and height were highly significantly correlated with the second principal component score (PC2), which led to the positive changes in soil N and P pool. Therefore, among the three forms of organic mat-ter, chicken manure influenced soil N and P contents and the related enzyme activities the most. Straw greatly influenced soil K and cellulose degradation-related enzymes, while biochar more evenly enhanced soil fertility which led to the most comprehen-sive gains in soil fertility. Straw or chicken manure, combined with biochar, more comprehensively improved soil fertility.