Effect Of Biochar On Dry Matter Production Of Soybeans With Different Phosphorus Efficiency

The effect of biochar and diammonium hydrogen phosphate(DAP) on dry matter accumulation of soybeans with different phosphorus(P) efficiency was studied using two soybean cultivars(the high P efficiency soybean Liaodou 13 and low P efficiency soybean Tiefeng 3).Research contents included agronomic traits, photosynthetic traits, dry matter accumulation condition and yield correlated characters. The results were as follows:Both biochar and DAP increased the plant height in early growth stage and stem diameter in late growth stage of two soybean cultivars, leaf net photosynthetic rate, stomatal conductance, transpiration rate and SPAD were also accelerated by biochar and DAP. Biochar and DAP could keep higher SPAD and superior photosynthetic traits in late growth stage of soybean, moreover, biochar mixed with DAP had better impact than their single treatment. Compared two soybean cultivars, low P efficiency soybean Tiefeng 3 was promoted greater than Liaodou 13 in leaf net photosynthetic rate and stomatal conductance.Dry matter weight of stem, leaf, petiole, root and pod of both soybean cultivars was accelerated by biochar and DAP, meanwhile, the accumulation and average accumulation rate of shoot biological yield was also promoted by biochar and DAP. Especially biochar mixed with DAP treatment increased the weight of vegetative organs in early growth stage and pod weight in late growth stage, and root/shoot ratio decreased in early stage.Through the comparison on yield corelated characters of two soybean cultivars in different treatments, pod number, grain number, grain weight and yield were all accelerated by biochar and DAP,and biochar mixed DAP treatment had te best effect. The increased yield range of Liaodou 13 and Tiefeng 3 was 13.2% and 28.0% respectively in biochar mixed DAP treatment.