玉米芯生物炭对辣椒连作土壤性质和辣椒生长的影响

以辣椒连作土壤为研究对象，添加不同量(5、10、20、30 t·hm^-2)的玉米芯生物炭，通过测定土壤基本理化性质、微生物量碳(MBC)、微生物量氮(MBN)和植株生长指标的变化，探讨生物炭施用对连作土壤和辣椒生长的影响。结果表明：与不添加生物炭的CK相比，添加适量生物炭显著(P<0.05)提高了辣椒连作土壤的有机碳(SOC)、全氮、全磷、有效磷和速效钾含量，但降低了全钾含量。施用生物炭较CK显著(P<0.05)降低了土壤MBC/MBN和土壤MBC/SOC。当生物炭添加量≥10 t·hm^-2时，土壤MBC、MBN含量较CK显著(P<0.05)增加；当生物炭添加量为10～20 t·hm^-2时，土壤MBN/TN较CK显著(P<0.05)提高。相关性分析表明，土壤MBC、MBN与土壤全氮、有机碳、全磷、有效磷呈极显著(P<0.01)正相关，与土壤全钾呈极显著(P<0.01)负相关。当生物炭用量为5～20 t·hm^-2时，辣椒植株的单株产量较CK显著(P<0.05)...

Effects of corncob biochar application on soil characteristics and pepper growth under continuous cropping

In order to investigate the effects of biochar application on soil physiochemical properties, soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and and plant growth indexes, different rates (5, 10, 20, 30 t·hm^-2) of corncob biochar were added to pepper continuous cropping soils in the present study. It was shown that application of appropriate rate of biochar significantly (P<0.05) increased the contents of soil organic carbon (SOC), total nitrogen, total phosphorus, available phosphorus and available potassium as compared with the CK treatment without biochar application, yet decreased the total potassium content in soil. The soil MBC/MBN and MBC/SOC were significantly (P<0.05) decreased with application of biochar as compared with CK. When the biochar addition rate was above or equal to 10 t·hm^-2, the soil MBC and MBN contents were significantly (P<0.05) increased as compared with CK. When the biochar addition rate was 10-20 t·hm^-2, the soil MBN/TN was significantly (P<0.05) increased as compared with CK. The correlationship analysis showed that the soil MBC and MBN were significantly (P<0.01) positively correlated with soil total nitrogen, organic carbon, total phosphorus and available phosphorus, and were significantly (P<0.01) negatively correlated with soil total potassium. When the application rate of biochar was 5-20 t·hm^-2, the pepper yield per plant was significantly (P<0.05) increased as compared with CK, and the highest value was recorded under the application rate of 20 t·hm^-2. But, the higher application rate did not support the further increase of pepper yield. In conclusion, the modest biochar application could improve soil micro-environment and soil fertility, promote pepper growth and increase pepper yield.