早稻稻草还田方式对晚稻产量及钾素吸收利用的短期效应

Short-term influence of early rice straw return approaches on the yield and potassium absorption and utilization of late rice

为了探明早稻稻草的高效还田方式,采用大田试验,研究了不同早稻稻草还田方式对晚稻产量、钾素农学效应、植株吸钾量和钾素利用率的影响,为南方稻田晚稻生产中如何利用早稻稻草提供指导。结果表明:稻草焚烧(SI)或稻草覆盖(SM)还田提高了钾素农学效应、产值、增产值和产投比,稻草覆盖(SM)还田还提高了吸钾总量和钾素利用率。通过计算农田钾素表观平衡,发现除稻草留高桩(HN)处理外的所有处理都出现了钾素亏缺,稻草全部焚烧(SI)、稻草留高桩部分焚烧(HI)和稻草覆盖(SM)处理钾素亏缺量小于稻草不还田(AK)处理。综合考虑产量、经济效益和钾素利用率等因素,南方双季稻区早稻稻草覆盖还田是最优的还田方式,对减少晚稻化学钾肥投入具有重要作用。

A ifeld experiment was conducted to study the effect of different approaches of early rice straw return on late rice yield, K agronomy efifciency, K uptake, and K use efifciency of late rice. This was done to identify efifcient approaches for returning early rice straw and provide guidance for early rice straw using in Southern China. The results showed that straw incineration （SI） and straw mulching （SM） treatments improved K agronomy efficiency, output value, increase value, and output/input ratio. The SM treatment also improved K uptake and K use efifciency. After the apparent K balance was calculated, shortage of potassium was found in all the treatments except for high stubble （HN） treatment. The shortage of soil potassium of SI, high stubble incineration （HI）, and SM treatments were lower than that of no straw returned （AK） treatment. In terms of the yield, economic beneifts, and K use efifciency, early rice straw mulching return is the most appropriate early rice straw return practice and it play an important role in reducing chemical potassium fertilizer application of late rice.