稻壳炭对红壤理化特性及芥菜生长的影响

本文探讨了不同热解温度制备的稻壳炭的基本性质,并通过盆栽试验研究了500℃热解稻壳炭添加量对南方红壤理化性质和芥菜产量的影响。结果表明:稻壳炭添加量3%、5%和10%三个处理显著改善了红壤的理化性质,土壤体积质量较对照处理依次降低0.11、0.28和0.42 g/cm~3,p H由4.5分别增加到7.5、7.8、8.4,CEC依次增加52.16%、187.02%和214.35%,土壤有机质、速效磷和速效钾显著增加,但稻壳炭添加量10%处理的土壤碱解氮含量降低。稻壳炭对芥菜的养分含量、产量等指标影响较为显著,随着施炭量的增加,芥菜的生物量增加,叶片全氮从1.63 g/kg增加到2.44 g/kg,全磷从2.32 g/kg增加到3.09 g/kg,全钾从47.1 g/kg增加到56.7 g/kg,产量由108.37 g/盆增加到608.7 g/盆。总之,添加5%的500℃热解稻壳炭有效改善了酸度较强的红壤的理化性质,促进了芥菜的生长和增收以及对氮磷钾养分的吸收和储存。在红壤改良上,稻壳炭的最佳添加比例为5%。

Effects of Rice Husk Biochar on the Physical and Chemical Properties of Red Soil and Mustard Growth

Ameliorating effects of biochar as a soil amendment vary with its feedstock, properties, application rate, reaction time with the soil, and soil properties. The objective of this study was to investigate the effects of rice husk biochar at different application rates on the physical-chemical properties and nutrient availability of red soil and mustard growth using pot experiment. The biochar prepared at 500℃ was applied at six rates, i.e. 0, 1, 2, 3, 5, and 10% (w/w) (C0, C1, C2. C3, C5 and C10). The results indicated that the physical-chemical properties of the red soil were significantly improved due to application of the biochar at C3, C5 and C10. The soil bulk density was reduced by 0.11g/cm3, 0.28g/cm3 and 0.42g/cm3, respectively, compared to C0. Soil CEC for C3, C5 and C10 treatments increased by 52.16%, 187.02% and 214.35%, respectively, compared to C0. Soil pH significantly increased from 4.5 for C0 to 8.4 for C10. The organic matter content, available P and available potassium of C3, C5 and C10 treatments increased significantly, but the alkali-hydrolysable nitrogen content decreased for C10 treatment compared to C0. Application of the biochar also increased the contents of nutrients in plant leaves and plant biomass yields. Leaf tissue N concentrations increased from 1.63 to 2.44 g/kg, leaf tissue P from 2.32 to 3.09 g/kg and leaf tissue K from 47.1 to 56.7 g/kg. The mustard yields increased significantly from 108.37 g/pot for C0 to 608.7 g/pot for C10. In conclusion, application of the biochar at 5% (w/w) was appropriate for the red soil with high acidity, low fertility, and poor water holding capacity. The biochar applied at this rate can promote mustard growth and increase uptake of N, P, K nutrients by the plant.