不同秸秆生物炭对水稻生长及土壤养分的影响

Effects of different straw biochars on rice growth and soil nutrients

【目的】探讨桑枝秆、木薯秆和甘蔗渣生物炭对水稻产量及稻田土壤养分的影响,为充分利用广西桑蚕、木薯和糖料蔗产业秸秆废弃物资源实现水稻增产增收提供理论依据。【方法】采用盆栽试验,以不添加生物炭为对照,设添加桑枝秆生物炭1.5%、3.0%和4.5%;添加木薯秆生物炭1.5%、3.0%和4.5%;添加甘蔗渣生物炭1.5%、3.0%和4.5%共9个秸秆生物炭处理,于水稻主要生育期内调查水稻生长状况,收获后进行考种测产,并分析土壤pH及养分含量的变化情况。【结果】与对照相比,施用桑枝秆和甘蔗渣生物炭提高了分蘖中期和齐穗期的水稻株高,也显著提高了成熟期水稻的有效穗数和成穗率(P<0.05,下同)。施用生物炭可增加水稻穗长、穗粒数和结实率(木薯秆生物炭3.0%和4.5%处理除外),对千粒重无显著影响(P>0.05)。除木薯秆生物炭4.5%和甘蔗渣生物炭1.5%处理外,其他生物炭处理均可显著提高水稻产量,且桑枝秆、木薯秆和甘蔗渣3种生物炭均在添加量为3.0%时增产幅度最大,分别比对照增产38.05%、28.24%和32.73%,以桑枝秆生物炭3.0%处理的增产效果最佳。施用生物炭整体上可提高土壤的全氮、有效磷和速效钾含量,降低全磷、全钾和碱解氮含量。各生物炭处理的土壤pH(甘蔗渣生物炭1.5%和3.0%处理除外)和有机质含量显著提高,以甘蔗渣生物炭对土壤有机质的提升效果最佳,桑枝秆生物炭对土壤pH的提高幅度最大。【结论】施用3种生物炭均有效提高了稻田土壤肥力及水稻产量,其中木薯秆生物炭对土壤全氮、有效磷和速效钾含量的提升作用较佳,桑枝秆生物炭对水稻产量的提升效果较优。

【Objective】In order to provided a reference for realizing the increase of rice yield and income by using straw waste in sericulture,cassava and sugarcane industries in Guangxi,the effects of mulberry branch,cassava stalk and bagasse biochars on rice production and soil nutrients were studied.【Method】The pot experiment was conducted,with no biochar added as control,nine straw biochar treatments were set with the mulberry branch biochar was added with 1.5%,3.0%and 4.5%,cassava stalk biochar was added with 1.5%,3.0%and 4.5%,bagasse biochar was added with 1.5%,3.0%and 4.5%.The growth of rice were investigated in the main growth period and the yield was measured after harvest.The changes of soil pH and nutrient contents were analyzed.【Result】Compared with control,application of mulberry branch and bagasse biochar treatments increased the height of rice plant in middle tillering and heading stage,and significantly improved the effective panicle number and heading rate of rice at the maturation stage(P<0.05,the same below).The spike length,grain number per panicle and seed setting rate of rice(except cassava stalk biochar 3.0%and 4.5%treatments)were increased under biochar treatments,but there was no significant effect on the thousand grains weight(P>0.05).The yield of rice(except cassava stalk biochar 4.5%and bagasse biochar 1.5%treatments)was significantly increased,with the biochar mulberry branch biochar,cassava stalk biochar and bagasse biochar all had the highest yield increase at the level of 3.0%,and increased by 38.05%,28.24%and 32.73%compared with control,respectively.Among them,3.0%mulberry branch biochar treatment increased the most.On the whole,application of biochar treatment increased the content of total nitrogen,available phosphorus and available potassium in soil,and decreased the content of total phosphorus,total potassium and alkali-hydrolyzed nitrogen in soil.pH(except bagasse biochar treatments 1.5%and3.0%)and organic matter content of soil were significantly increased.Among them,bagasse biochar had the best effect on increasing the soil organic matter and mulberry branch biochar had the best effect on increasing the soil pH.【Conclusion】Appropriate application of three kinds biochar could effectively improve the soil fertility and rice yield.Among them,the cassava stalk biochar had better effects on increasing the total nitrogen,available phosphorus and available potassium in soil,and the mulberry branch biochar had better effects on increasing the rice yield.