连续施用生物炭对土壤理化性质及氮肥利用率的影响

摘要

为探讨连续施用生物炭及生物炭不同用量对土壤肥力及氮肥利用率的影响,在沈阳农业大学后山棕壤新型肥料试验基地(始建于2013年)布置生物炭用量定位试验,设置4个生物炭用量梯度0,1.5,3,6 t·hm-2,研究不同用量生物炭对棕壤理化性质、玉米产量及氮肥利用率的影响.结果表明:生物炭对玉米苗期土壤含水量的影响不大,随着生育期的推进,逐渐表现出其保水性能;添加生物炭可以降低土壤容重,不同用量生物炭处理的土壤容重较NPK处理平均降低了6.04％,且容重随施炭量的增加而降低;施用生物炭可以提高土壤pH值、 有机质和全氮含量,与NPK处理相比,C2NPK、C3NPK处理土壤有机质含量分别提高了31.20％、32.61％,全氮含量分别提高了6.73％、6.09％,差异显著;同时施用生物炭可以促进土壤矿质态氮的缓慢释放.连续添加生物炭可以促进玉米的生长发育,提高玉米产量,2013年,不同用量生物炭处理间差异未达显著水平.2014年,生物炭处理的玉米产量随施炭量的增加而升高,C3NPK、C2NPK处理的玉米产量分别较NPK、C1NPK处理提高了21.36％、10.99％与17.19％、7.18％.2015年,仍以C3NPK处理玉米产量最高,较NPK处理增产9.09％.无论是否将生物炭中氮含量计入施氮总量,生物炭处理均能提高氮肥利用率.%The aim of this study is to explore the effects of continuous different application amounts of biochar on soil fertility and nitrogen fertilizer use efficiency. Fixed located field plot on brown earth was used in newly emerging fertilizer experiment base of Shenyang Agricultural University, Liaoning Province, China. The effects of different dosages of biochar on soil physical and chemical properties, maize yield and nitrogen use efficiency are studied by using four biochar levels of 0 t·hm-2, 5 t·hm-2, 3 t·hm-2 and 6 t·hm-2. The results showed that the effect of biochar on the soil water content of maize seedling stage was not significant, but the water retention performance was increasing gradually. Continuous addition of biochar to the soil reduced soil bulk density. And soil bulk density of biochar was 6.04％ lower than that of NPK. The soil pH, organic matter and total nitrogen were significantly improved by the addition of biochar. Compared with NPK treatment, the soil organic matter of C2NPK and C3NPK increased by 31.20％ and 32.61％ respectively, and the total nitrogen increased by 6.73％ and 6.09％, respectively. And biochar promoted the slow release of ammonium and nitrate nitrogen in soil. Continuous application of biochar on soil could promote the growth and development of maize, increase the yield of maize. In 2013, the difference between the different amounts of biochar treatments was not significant. In 2014, the yield of C3NPK and C2NPK increased by 21.36％, 10.99％ and 17.19％,7.18％, respectively, compared with those of NPK and C1NPK. In 2015, the yield was still the highest with C3NPK, which was 9.09％ higher than that of NPK. Whether or not the nitrogen content of biochar was included in the total amount of nitrogen fertilizer, biochar treatment could improve the nitrogen use efficiency.