寒地稻秸还田与施钾肥对土壤水溶性钾和水稻产量的影响

Effect of rice straw retention and potassium fertilizer application in cold region on soluble potassium content in the soil solution and rice yield

秸秆还田或施钾肥可增加作物产量,而土壤溶液是作物自土壤吸收养分的主要媒介,养分含量直接反映土壤养分供应状况。为研究秸秆还田和施钾肥对水稻生育期间土壤水溶性钾浓度和产量的影响,小区试验设置高量秸秆还田(S2)、低量秸秆还田(S1)和不还秸秆(S0)三个处理,盆栽试验在高量秸秆还田(S2)和不还秸秆(S0)基础上设置5个钾肥施用水平。结果表明,随着水稻生育时间延长土壤水溶性钾浓度逐渐降低,对数方程对土壤溶液中速效钾的变化动态拟合效果良好。秸秆还田显著增加土壤水溶性钾浓度,随秸秆还田量增加而增加,增施钾肥能够显著增加土壤水溶性钾浓度,秸秆还田和施钾肥并没有改变水稻生育期间土壤水溶性钾浓度变化趋势。秸秆还田和增施钾肥均能够增加水稻产量,在钾肥施用量较低水平,秸秆还田增产作用显著;秸秆还田量达到6.25 t·hm-2后继续增加秸秆量水稻产量无明显增加。

Straw retention or potassium fertilizer application can increase crop yield, and soil solution is the main way to absorb nutrients from soil for crop, the level of nutrient content in the soil solution can directly reflect soil nutrient supply situation. To study the effects of straw retention and potassium fertilizer application on soluble potassium content in the soil solution and yield during rice growth, the plot experiment set three treatments： high amount of straw retention （$2）, low amount of straw retention （$1） and straw removal （SO）. The pot experiment set five potassium fertilizer application levels, and the experiment was divided into two subgroups： high amount of straw retention （$2）, straw removal （SO）. The results showed that the soluble potassium content in the soil solution decreased with the rice growth, logarithmic equation could well fit the soluble potassium changes in the soil solution. The soluble potassium content in the soil solution significantly increased with straw retention, and increased with the increasing amount of straw retention. With the increasing of potassium fertilizer application, the soluble potassium in the soil solution significantly increased, straw retention and potassium fertilizer application did not affect the trend of soluble potassium changes dudng rice growth. Straw retention and increasing potassium fertilizer could increase dce yield, straw retention could significantly increase rice yield in the low level of potassium application. There was no significant increase in rice yield when the amount of straw retention reached 6.25 t· hm^-2.