不同生物炭用量对湘西植烟土壤养分的影响

通过大田试验,设置不施肥(T1),常规施肥(T2),减氮5%、10%、15%、20%常规施肥基础上施生物炭450(T3)、900(T4)、1 350(T5)、1 800(T6)kg/hm~26个处理,研究生物炭对土壤养分的影响,以确定最适合湘西烤烟的生物炭用量。结果表明,随着生物炭用量的增加,各生育时期土壤有机质含量总体均呈现增加的趋势,施用生物炭处理有机质含量均大于不施肥和常规施肥处理,总体以移栽后60 d时较大,此时T6处理有机质含量最高,达37.83 g/kg,比不施肥处理增加24.72%,比常规施肥处理增加22.11%;与不施肥和常规施肥处理相比,施用生物炭可增加土壤碱解氮、速效磷和速效钾含量,且其随着生物炭用量增加先增加后降低,总体上,土壤碱解氮、速效磷含量均以T4、T3处理较高,速效钾含量以T5处理效果最佳,T4处理次之;施用生物炭可以增加土壤pH值和C/N,且其均随生物炭用量增加而增加,施用生物炭处理土壤pH值平均各生育时期分别比不施肥和常规施肥处理增加7.65%~13.75%和5.28%~11.25%。综合分析,施用生物炭可提高土壤养分含量,以T4处理效果最好,适宜在产区进行示范应用。

Effects of Different Amounts of Biochar on Soil Nutrients of Flue-cured Tobacco in West Hunan

In order to determine the most suitable biochar dosage for flue-cured tobacco in West Hunan, a field experiment was conducted with different amounts of biochar T1:no fertilizer,T2:conventional fer-tilization,T3—T6:450(T3)、900(T4)、1350(T5)、1800(T6) kg/ha biochar based on conventional fer-tilization with nitrogen amount reduced by 5%,10%,15%,20%] . The results showed that on the whole, with the increase of biochar amount,the soil organic content increased,and the organic content order was T3—T6>T1,T2,the organic content was the highest at 60 d after transplanting,the organic content of T6 treatment was the highest with 37. 83 g/kg at this time,which increased by 24. 72%,22. 11% compared with T1,T2 treatments. Compared with T1 and T2 treatments,the application of biochar increased soil available nitrogen,phosphorus and potassium contents,which first increased and then decreased with the increase of biochar amount, soil available nitrogen, phosphorus contents of T3 and T4 treatments were higher,available potassium content of T5 treatment was the best,followed by T4 treatment. The pH value and the ratio of carbon to nitrogen of soil were increased with the application amount of biochar,and the pH value increased by 7 . 65%—13 . 75% and 5 . 28%—11 . 25% compared with T1 and T2 treatments respectively. In short,the application of biochar could notably improve the soil nutrients,and T4 treatment worked best to application for demonstration in the region.