Abstract:

Biochar has the effect of improving soil， saving water， retaining fertilizer and increasing yield. In response to the problem of low water and fertilizer retention capacity of sandy soil in Yulin， the effects of biochar application amounts and drip irrigation amounts on soil physicochemical characters and potato growth were studied by combining biochar with drip irrigation fertilization. There were two irrigation levels： 80% ET_C（W1） and 100% ET_C（W2）， and five carbon application levels： 0 （B0）， 10 （B10）， 20 （B20），30 （B30） and 50 t·hm^-2 （B50）， a total of 10 treatments. Soil bulk density， organic carbon， soil water content， available potassium， nitrate nitrogen， dry matter accumulation amount and yield were observed during the growth period. The results showed that soil bulk density in 0—20 cm soil layer was decreased significantly with the increase of biochar， while soil porosity， soil organic carbon content and the content of available potassium were increased significantly， and the content of NO{}_{\mathrm{3}}^{-}-N and soil water content in the 0—20 cm soil layer were first increased and then decreased with the increase of biochar. With the increase of irrigation amount， soil bulk density in the 0—20 cm soil layer was decreased， and soil porosity and water content were increased. The effect of biochar application on potato dry matter accumulation amount was significant only at the late growth stage， which was first increased and then decreased with the increase of biochar. The potato tuber yield and water use efficiency were first increased and then decreased with the increase of biochar， and the tuber yield was increased with the increase of irrigation amount， and yield reached the maximum of 58 263.89 kg·hm^-2 at W2B30 treatment， but there was no significant differences with W1B20， W1B30 and W2B20， while the maximum water use efficiency was W1B20 treatment， Therefore， considering the yield， water use efficiency and economy， W1B20 treatment could be a suitable water-carbon combination under the experimental conditions.

Key words: potato, biochar, drip irrigation amounts, soil properties, growth, yield

摘要：

生物炭具有改良土壤和节水保肥增产的效应，针对榆林沙土地持水保肥能力低的问题，将滴灌施肥与生物炭相结合，探究生物炭施用量和滴灌量对土壤理化性质和马铃薯生长的影响。大田试验设置2个滴灌量水平80% ET_c （W1）和100% ET_c （W2），5个生物炭水平0（B0）、10（B10）、20（B20）、30（B30）和50 t·hm^-2（B50） ，共10个处理，生育期内对土壤容重、孔隙度、有机碳、土壤水分、速效钾、硝态氮、干物质累积量及产量等进行观测。结果表明，随着生物炭施用量的增加，0—20 cm土层土壤容重显著降低，土壤孔隙度、土壤有机碳含量和土壤速效钾含量显著增加，土壤硝态氮含量和含水量先增加后减小。随着滴灌量增加，0—20 cm土层土壤容重降低，土壤孔隙度和含水量增大。生物炭的施用仅对生长后期马铃薯干物质累积量促进效果显著，表现为随着生物炭施用量的增加先增加后减少。马铃薯块茎产量和水分利用效率随着施炭量的增加先增加后减小，马铃薯块茎产量随着滴灌量的增大而增大，W2B30处理下最高，为58 263.89 kg·hm^-2，但与W1B20、W1B30、W2B20处理无显著差异，而水分利用效率最大值出现在W1B20处理，所以从产量、水分利用效率以及经济的角度考虑，W1B20可作为本试验条件下较适宜的水炭组合。

关键词: 马铃薯, 生物炭, 滴灌量, 土壤性质, 生长, 产量