生物炭对土壤水肥利用效率与番茄生长影响研究

通过设置不同生物炭施用量的野外大田小区试验,研究不同处理砂壤土物理性质及水肥的变化规律。试验共设5个处理,3个重复:不施生物炭(CK),生物炭施用量分别为10 t·hm-2(T1)、20 t·hm-2(T2)、40t·hm-2(T3)、60t·hm-2(T4)。结果表明:施用生物炭能明显减小土壤容重,增大土壤孔隙度,增加土壤含水率,与对照(CK)相比,耕作层(0~20 cm)土壤容重T4减小最大,0~10 cm减小23%,0~20cm减小30%;孔隙度T4增加最大,0~10 cm增加14%,0~20cm增加19%。施用生物炭明显提高了土壤的水分与肥料利用效率,与对照(CK)相比,处理组的水分和肥料利用效率分别最少提高27.7%和87.4%,其中T3增幅最大。生物炭能促进作物生长发育,提高作物产量,本试验番茄产量T3增幅最大,增幅为56.1%。综上所述,生物炭能改变土壤的物理性质,提高水肥利用率,减少肥料淋失,其中T3在这些指标中增幅最为明显,因此40 t·hm-2生物炭用量是改良砂壤土最为合适的用量。

Effects of Biochar Amendment on Soil Water and Nutrient Utilization Efficiencies and Tomato Growth

Biochar added to soil has the potential to hold water and retain nutrients. However, the effects of biochar on soil water and nutrient utilization efficiencies were not well understood. A field experiment was carried out to examine changes of physical properties and water and nutrient bearing capability of sandy loam under different application rates of biochar. The experiment had 5 treatments with 3 replication, including no biochar(CK), 10 t·hm^-2(T1), 20 t·hm^-2(T2), 40 t·hm^-2(T3) and 60 t·hm^-2 of biochar(T4). Application of biochar reduced soil bulk density, but increased soil porosity and moisture content. Such effects were found to be the greatest in the T4 treatment, in which bulk density was reduced by 23% in 0~10 cm, and by 30% in 0~20 cm, while the porosity was increased by 14% in 0~10 cm, and by 19% in 0~20 cm as compared with the control. Biochar addition enhanced soil water and nutrient utilization efficiency by at least 27.7% and 87.4%, respectively. Also, biochar improved tomato growth and yield, with the greatest effects observed in the T3 treatment, a 56.1% increment over the control. In conclusion, biochar could improve soil physical properties, increase utilization efficiency of soil water and nutrients. The optimum biochar rate would be 40 t·hm^-2 for sandy loam.