猪炭和竹炭的理化特性差异及其对菜地土壤氨挥发的影响

Physiological and biochemical characteristics of pig versus bamboo biochars and their effects on ammonia volatilization in greenhouse vegetable production

以动物源的猪炭和植物源的竹炭为试验材料,探讨不同原材料制备所得生物质炭的特性差异。同时以南方设施菜地为研究对象,试验以不施用生物质炭处理为对照(ck),通过田间小区试验研究生物质炭的种类(猪炭和竹炭)和施用方式(一次施用和分批施用)对空心菜Ipomoea aquatica-小青菜Brassica chinensis轮作土壤氨挥发的影响。结果表明:猪炭的含磷量较高,含碳量较低,灰分含量高,与竹炭的高含碳量和低灰分量差别较大。土壤氨挥发速率与土壤温度呈极显著相关(P<0.01),空心菜季土壤氨挥发损失高于小青菜季。猪炭和竹炭处理显著(P<0.05)降低了两茬空心菜季土壤氨挥发,而对小青菜季土壤氨挥发没有显著性影响。与分批施用处理相比,一次施用处理下第1茬空心菜土壤氨挥发分别减少了28.7%和13.3%,且猪炭的效果优于竹炭。对于第2茬空心菜土壤氨挥发,各生物质炭处理间没有显著性差异。与对照相比,一次性施用20 t·hm^(-2)猪炭处理下空心菜-小青菜轮作周期土壤氨挥发总损失降低了41%。与竹炭相比,猪炭对土壤氨挥发的抑制效果更佳。

To evaluate the effect of feedstock materials on characteristics of biochar products from a pig-derived biochar（ PB） and a bamboo-derived biochar（BB）, biochar properties were evaluated and compared in a laboratory study. A field experiment was also carried out to evaluate the effect of PB and BB on soil ammonia volatilization in an Ipomoea aquatica-Brassica chinensis rotation system in a greenhouse at Banqiao Town,Lin＇an City, Zhejiang Province, China. Treatments included（1） a control（no biochar）;（2） one application of 20 t·hm^-2PB（20-0-PB） prior to the first I. aquatica crop;（3） one application of 20 t·hm^-2of BB（20-0-BB）prior to the first I. aquatica crop;（4） two applications of PB with 10 t·hm^-2being applied prior to the I. aquatica season and the remaining PB being applied prior to the B. chinensis season at an application rate of 10 t·hm^-2（10-10-PB）; and（5） two applications of BB with 10 t·hm^-2being applied prior to the I. aquatica season and the remaining BB being applied prior to the B. chinensis season at an application rate of 10 t·hm^-2（10-10-BB）. Results showed that PB had higher contents of phosphorus and ash as well as a lower content of carbon than those of BB; whereas, BB had a higher carbon content and a lower ash content than those of PB. The ammonia volatilization rate had a highly significant correlation（P0.01） with soil temperature, and the ammonia volatilization losses in the Ipomoea aquatica crop season were higher than in the Brassica chinensis crop season. The PB and BB treatments significantly（P〈0.05） reduced ammonia volatilization losses in the I.aquatica crop season, but had no significant effect in the B. chinensis crop season. Compared with the 10-10-PB or 10-10-BB treatments, ammonia volatilization losses were significantly（P〈0.05） reduced with 20-0-PB（28.7%） and 20-0-BB（13.3%） treatments in the first I. aquatica crop season, and the PB treatment was more effective than the BB treatment. No significant differences between PB and BB treatments in the second I.aquatica crop season were found. Compared with the control, the 20-0-PB treatment reduced ammonia volatilization losses 41% over the whole rotation. In conclusion, pig biochar treatments appeared to be more effective than bamboo biochar treatments in reducing ammonia volatilization losses from the soil.