梨园秸秆还田腐解特征及对土壤性状的影响研究

为探究梨园秸秆还田腐解特征及对土壤理化性状和生物性状的影响,在梨园布置覆膜对照(CK)、秸秆覆盖(S)、秸秆覆盖+腐解菌肥(S-BM)、双倍秸秆覆盖+腐解菌肥(2S-BM)田间试验。结果表明:秸秆覆盖150天后,S-BM处理的腐解率为62.4%,S和2S-BM处理的腐解率均为50%,氮、钾释放率以S-BM处理最高;秸秆覆盖提高了土壤最低温,降低了土壤最高温,减小了土壤温度振幅;2S-BM处理显著降低了土壤体积质量,提高了土壤水溶性有机碳含量;秸秆覆盖显著增加了0~5 cm土层有机碳含量,2S-BM处理对0~15 cm土层速效养分含量的提升效果显著,S和S-BM处理显著提高了0~5 cm土层速效钾含量;2S-BM处理的土壤细菌、真菌数量以及微生物生物量碳、氮含量在梨树生育后期明显提高;2S-BM、S-BM和S处理分别能增产86.9%、17.8%和28.7%。秸秆覆盖对土壤的改善是由上到下的,当梨园秸秆还田量为45 000 kg/hm2时,土壤的改良效果非常明显。

Effects of Straw Decomposition Characteristics on Soil Properties of Pear Orchard

In order to investigate the effects of the straw decomposition on soil physical, chemical properties and biological properties of pear orchard, field experiments were carried out, treatments were included plastic mulching(CK), straw mulching(S), straw mulching + decomposing bacterial manure(S-BM), double straw mulching + decomposing bacterial manure(2S-BM). The results showed that the decomposition rate was 62.4% for S-BM treatment, while were 50% for S and 2S-BM treatments. Release rates of nitrogen and potassium of S-BM treatment were the highest under straw mulching after 150 d. Straw mulching increased soil lowest temperature, decreased soil highest temperature and temperature amplitude. The content of soil dissolved organic carbon increased while soil bulk density decreased significantly in 2S-BM treatment. Straw mulching increased soil organic carbon content at 0 – 5 cm, 2S-BM treatment enhanced soil available nutrient content at 0 – 15 cm, and S and S-BM increased soil available potassium content at 0 – 5 cm, significantly. 2S-BM treatment increased the number of soil bacteria, fungi and the contents of soil microbial biomass carbon and nitrogen in the late growth stage of pear tree. In addition, pear yields of 2S-BM, S-BM and S treatments were 86.9%, 17.8% and 28.7% higher than the CK respectively. Straw mulching improved soil properties from top to bottom, and the effect of soil improvement was very obvious when the amount of returning straw was 45 000 kg/hm2 in pear orchard.