生物炭对土壤理化性质及橡胶幼苗生物量的影响

Effect of Biochar on Soil Properties and Rubber( Hevea brasilensis)Seedling Biomass

为探讨生物炭对西双版纳土壤性质及橡胶（Hevea brasiliensis）幼苗生长的影响,评价其对橡胶人工林固碳增汇的潜在能力,将不同量的生物炭（与土壤质量比分别为CK：0;B2.5：2.5%;B5：5%）与复合肥（0 kg/hm2;F：300kg/hm2）交互（共6个处理：CK,F,B2.5,B2.5＋F,B5,B5＋F）加入土壤中进行1 a的橡胶幼苗盆栽实验研究,对土壤进行水分、温度、土壤呼吸速率以及养分测定,对幼苗进行地径、株高、光合速率以及生物量的测定。结果表明：生物炭增加了土壤p H值,降低了土壤容重;显著提高土壤含水量（雨季较对照提高了26.9%-76.3%,旱季则提高了30.8%-63.5%）;生物炭显著增加土壤全碳和全磷含量,降低了土壤硝态氮,B5和B5＋F处理的土壤有效磷显著高于对照,分别是对照的18.3倍和16倍;在雨季和旱季土壤呼吸速率均表现为：B5＋F〉B2.5＋F〉B5〉F〉B2.5〉CK,CK的土壤呼吸速率显著低于其他所有处理;施肥处理的幼苗生物量显著高于CK和所有单施生物炭处理,以B2.5＋F处理效果更明显;施肥与生物炭均显著提高了橡胶幼苗光合速率。综上所述,生物炭可以改善土壤性质,保持和提高水分和大部分土壤养分,促进植物生长,具有促进地上固碳及土壤固碳的潜力。从本短期的实验来看,单施生物炭不能促进橡胶幼苗生长,与肥料配合使用更能促进橡胶幼苗生长。

A pot experiment was carried out with biochar（ CK： 0; B2. 5： 2. 5%; B5： 5%; w / w） and fertilizer（ 0 kg /hm2; F： 300 kg /hm2）（ totally 6 treatments： CK,CK ＋ F,B2. 5,B2. 5 ＋ F,B5 and B5 ＋ F） during 2014. The study investigated the effects of biochar application in rubber plantation on i） enhancing carbon sequestration ii） soil properties and iii） rubber seedling biomass. The study revealed that biochar application significantly increased soil p H,soil water content（ 26. 9% - 76. 3% in rainy season and 30. 8% - 63. 5% in the dry season,respectively）,Soil C,Phosphorus and reduced soil bulk density,soil nitrate. Soil available phosphorus of B5 and B5 ＋ F treatments was raised to 18. 3 and 16 folds as compared to the control. Soil respiration in the dry and rainy season showed the same pattern： B5 ＋ F〉 B2. 5 ＋ F 〉B5 F〉 B2. 5 〉CK,the control was significantly lower than any other treatments. Rubber seedling biomass of treatments with fertilizer showed a great difference from the control and treatments with biochar alone,and B2. 5 ＋ F was more remarkable. Both biochar and fertilizer also enhanced seedling photosynthetic rate dramatically. It was concluded that biochar changed the soil properties（ soil moisture and most of soil nutrients that promote the growth of plants） and has a potential to improve carbon sequestration of both above and below ground. For this reason,it is suggested that adding biochar with fertilizer rather than alone could enhance rubber seedling growth.