烟杆生物炭对砒砂岩与沙复配土壤理化性状及玉米生长的影响

为明确施用生物炭对砒砂岩与沙复配土壤水分保持及肥力提升的影响,采用盆栽试验,研究了不同生物炭施用量(0,10,20,30,50g/kg(以风干土计))对砒砂岩与沙复配土壤理化性状及玉米生长的影响。结果表明:在种植玉米一季后,施用生物炭可显著降低复配土壤容重,尤其当生物炭施用量达到30g/kg时,土壤容重可降低至1.37g/cm3,但当生物炭施用量增加到50g/kg时,土壤容重又出现增加的趋势;土壤田间持水量随生物炭施用量的增加呈显著增加趋势,但当施用量增加到50g/kg时又会出现下降趋势;土壤pH、全盐量随生物炭添加量的增加显著增加,尤其当生物炭添加量为50g/kg时,土壤pH可达8.80,全盐量可达2.51g/kg;土壤有机质、有效磷、速效钾含量也随生物炭施用量的增加而显著增加,但有效磷在生物炭施用量增加至50g/kg时出现下降趋势。进一步分析不同生物炭处理对玉米生物量的影响,发现玉米根干重、地上部分干重、百粒重、单株产量均随生物炭施用量的增加呈显著增加趋势,但当生物炭施用量增加到50g/kg时,上述各指标反而显著降低。生物炭对于砒砂岩与沙复配土壤理化性状、水分保持、肥力提升、作物生长及产量等诸多方面都有明显改善效果,在施用过程中需要注意使用量,在本试验条件下,生物炭推荐施用量为30g/kg干土。

Influence of Tobacco Biochar on Soil Physic-chemical Properties and Maize Growth in the Soil Composited with Feldspathic Sandstone and Sand

The aim of this study was to investigate the effect of biochar application on the water holding capacity and fertility of the soil composited with feldspathic sandstone and sand. A pot experiment with five treatments [0 g/kg biochar (CK), 10 g/kg biochar (T10), 20 g/kg biochar (T20), 30 g/kg biochar (T30), 50 g/kg biochar (T50)] was conducted over a corn growing season. Results showed that the application of biochar significantly decreased soil bulk density, but it was not a linear correlationship between the reduction of soil bulk density and biochar application rates. Specifically, soil bulk density was the minimum with 30 g/kg biochar applied, but 50 g/kg biochar application instead increased soil bulk density. There was a positive correlation between field water capacity and biochar application rates ranging from 0 g/kg to 30 g/kg, but the application of 50 g/kg biochar decreased soil field water capacity. Soil pH, total salt content, organic matter content and available potassium content increased with the increases of biochar application rates. Soil available phosphorus content firstly increased with biochar application rate but then decreased when 50 g/kg biochar was applied. Briefly, soil pH, total salt content were 8.80, 2.51 g/kg respectively with 50 g/kg biochar applied. Furthermore, it was also found that the dry weight of maize roots, the dry weight of maize aboveground part, the 100-grain weight and the yield per plant showed a significant increase with the increases of biomass application rates ranging from 0 g/kg to 30 g/kg, but the application of 50 g/kg biochar decreased these biomass indexes significantly. Overall, the application of biochar could improve soil physicochemical properties and fertility and the growth and yield of maize, but the effect would be lowered when biochar application rate is more than 30 g/kg. Accordingly, the recommended biochar application rate is 30 g/kg to improve soil quality and crop yield under the present experimental conditions.