Abstract:

The effects of cold-adapted microbial consortium HT20 on rice straw decomposition, nutrient release characteristics and soil nutrient dynamics in the coastal rice area of eastern Hebei were investigated. The experiment adopted the litter bag method, and set up three treatments: straw returning to the field without straw-decomposing inoculants（CK）, straw returning to the field with the application of Nongfukang（JF） and straw returning to the field with the application of HT20（JH）. Straw and soil samples were partially removed for analysis at the transplanting stage, tillering stage, jointing stage, booting stage, heading stage, milk ripening stage, and the maturation stage. Then, the straw mass, nitrogen, phosphorus, and potassium nutrient residue rates for the straw and soil nutrient content were determined. Compared with CK and JF treatment, the residual rate for straw mass in the JH treatment decreased by 9.01%-24.08% and 4.68%-11.31% during the sampling period respectively, the residual rate for straw nitrogen decreased by 15.56%-24.94% and 26.54%-36.31% during the transplanting stage and jointing stage, the residual rate for straw phosphorus decreased by 9.68% and 11.28% at the jointing stage, the residual rate for straw potassium was no significant difference among them, the residual rates of nitrogen, phosphorus and potassium increased negatively in the later stage. Compared with CK and JF treatment, the soil available nitrogen contents in the JH treatment increased by 53.33% and 4.55% at the tillering stage, respectively; the soil available phosphorus content increased by 195.62% and 65.80% at the jointing stage, and increased by 138.14% and 195.62% at the heading stage, respectively; the soil available potassium content increased by 7.64%-168.87% and 29.34%-179.30% during the sampling period, respectively. Compared with CK and JF treatment, the number of tillers in the JH treatment significantly increased by 14.10% and 16.57%, and the rice yield increased by 11.25% and 17.11%. It can be seen that the cold-adapted microbial consortium（HT20） could speed up the decomposition process of returning straws and the release of straw nutrients, improve soil fertility, promote rice tillering and growth, and then increase rice yield.

Key words: rice, cold-adapted microbial consortium, HT20, straw decomposition, nutrients release, soil nutrients, coastal rice area in eastern Hebei

摘要：

为探讨低温复合菌系HT20对冀东稻区还田秸秆的腐解、养分释放及土壤养分动态变化的影响，在冀东滨海单季稻区进行田间试验，采用秸秆网袋填埋法，设置秸秆还田（CK），秸秆还田配施“农富康”（JF）和秸秆还田配施HT20（JH）3个处理，分别于水稻移栽期、分蘖期、拔节期、孕穗期、抽穗期、乳熟期和成熟期取秸秆和土壤样品，测定秸秆质量残留率，秸秆中氮、磷、钾养分残留率和土壤养分含量。结果表明，相比CK和JF处理，JH处理下秸秆质量残留率分别低9.01%~24.08%和4.68%~11.31%，秸秆氮残留率在移栽期和拔节期分别低15.56%~24.94%和26.54%~36.31%，秸秆磷残留率在拔节期分别低9.68%和11.28%，秸秆钾残留率差别不大，氮、磷、钾残留率在后期有负增长现象。相比CK和JF处理，JH处理土壤碱解氮含量在分蘖期分别增加53.33%和4.55%，土壤速效磷含量在拔节期分别增加195.62%和65.80%，在抽穗期分别增加138.14%和195.62%；在全生育期内土壤速效钾含量分别增加7.64%~168.87%和29.34%~179.30%。相比CK和JF处理，JH处理水稻分蘖数显著增加14.10%和16.57%，水稻产量显著提高11.25%和17.11%。可见，低温复合菌系HT20能够加快还田秸秆的腐解进程和秸秆养分释放，改善土壤肥力，促进水稻分蘖和生长，进而提高水稻产量。

关键词: 水稻, 低温复合菌剂, HT20, 秸秆腐解, 养分释放, 土壤养分, 冀东稻区