生物炭施用量对冬小麦产量及水分利用效率的影响研究

通过田间定位试验研究不同用量生物炭施用及传统秸秆还田对黄土高原旱地冬小麦生育期内土壤水分、养分及产量和水分利用效率的影响。试验设置5个处理,分别为对照(CK)、生物炭施用量为15 t·hm-2(BC1)、30 t·hm-2(BC2)、45 t·hm-2(BC3)及秸秆还田(SR)。试验结果表明,土壤硝态氮、铵态氮及速效钾、有机质含量在小麦整个生育期内均随生物炭施用量的增加而增加;土壤储水量(0～200 cm)及速效磷含量随生物炭施用量的增加先增加后减少;产量及水分利用效率随生物炭施用量的增加先增加后减少,当生物炭用量为30 t·hm-2时,产量及水分利用效率最大,分别为6 640 kg·hm-2、18.1 kg·hm-2·mm-1,比对照(CK)分别显著增加17.2%、17.8%;秸秆还田(SR)使作物增产10.5%,但对水分利用效率影响并不显著。因此,施用适量生物炭在改善土壤水肥特性的同时,能够显著提高作物产量及水分利用效率。

Effects of biochar levels on winter wheat yield and water-use efficiency in Loess Plateau

A field trial was conducted to study the effects of biochar application rates and the straw-return on soil water content, soil nutrient, crop yield, and water use efficiency. There were five treatments:no biochar(CK), 15 t·hm^-2 biochar(BC1), 30 t·hm^-2biochar(BC2), 45 t·hm^-2 biochar(BC3), and straw-return. Results showed that the soil NO^-₃-N, NH⁺₄-N, available K, and organic matter content increased with increasing application rates of biochar in all growth stages of wheat.Soil water storage, available P, and crop yield, water-use efficiency increased initially but decreased subsequently with increasing application rates of biochar. Compared to the control and other biochar rates,the 30 t·hm^-2 of biochar significantly achieved peak yield (a 17.2% increase over CK to 6 640 kg·hm^-2) and water-use efficiency (an increase of 17.8% to 18.1 kg·hm^-2·mm). The straw-return increased yield by 10.5% but no effect on the water-use efficiency. Therefore, applying the appropriate rate of biochar can significantly improve soil fertility, crop yield, and water-use efficiency.