Effects Of Organic Fertilizer Application On Growth And Nitrogen Fertilizer Utilization Of Mung Bea

As the largest consumer of nitrogen fertilizer in the world,although the application of nitrogen fertilizer plays a crucial role in ensuring food security in China,over-application of nitrogen fertilizer can cause a number of problems such as low fertilizer efficiency,decreased soil productivity and pollution of the environment.In order to advocate green and sustainable Chinese modern agriculture,promoting the application of organic fertilizers has become a basic national policy for agricultural production in China.Therefore,under the condition of ensuring food security in China,it is very necessary to promote organic fertilizer and nitrogen fertilizer application pattern to improve the utilization of nitrogen fertilizer efficiency and reduce of environmental pollution.The experiment was based on ¹⁵N isotope tracing technology to study the effect of different organic fertilizer and nitrogen fertilizer on the growth and nitrogen fertilizer utilization of mung bean.10 treatments were set up,namely CK:no fertilizer control（0 kg/hm²）,T1:normal nitrogen fertilizer application（193.97kg/hm²+0 kg/hm²）,T2:nitrogen fertilizer+humic acid（107.76 kg/hm²+2000kg/hm²）,T3:nitrogen fertilizer+bio-organic fertilizer（107.76 kg/hm²+1460 kg/hm²）,T4:nitrogen fertilizer+biochar（107.76 kg/hm²+4706 kg/hm²）,T5:nitrogen fertilizer+straw organic fertilizer（107.76 kg/hm²+3077 kg/hm²）,T6:nitrogen fertilizer+humic acid（86.21 kg/hm²+2500 kg/hm²）,T7:nitrogen fertilizer+bio-organic fertilizer（46.34 kg/hm²+2500 kg/hm²）,T8:nitrogen fertilizer+biochar（148.17kg/hm²+2500 kg/hm²）,T9:nitrogen fertilizer+straw organic fertilizer（123.92kg/hm²+2500 kg/hm²）.To study the utilization,residual and loss of nitrogen fertilizer under different treatments and the effects on dry matter translocation,leaf area,stem thickness,photosynthetic potential,wet basis moisture content and stem-sheath matter output and transportation rate of mung bean.The main findings are as follows:（1）The leaf area and photosynthetic potential of different organic fertilizer with nitrogen fertilizer treatments showed a trend of increasing and then decreasing throughout the reproductive period.Compared with the control CK treatment,the seedling stage T9 treatment,the branching stage T2 treatment and the pod stage T4 and T9 treatments were better,with an increase of 5.11%to 31.82%,respectively.（2）The leaf area and photosynthetic potential of different organic fertilizer with nitrogen fertilizer treatments showed a trend of increasing and then decreasing throughout the reproductive period.Compared with the control CK treatment,the seedling stage T9 treatment,the branching stage T2 treatment and the pod stage T4 and T9 treatments were better,with an increase of 5.11%to 31.82%,respectively.（3）Compared to normal fertilization T1 treatment,T6 and T9 treatments showed a significant（P<0.05）increase in stem-sheath matter output and transportation rate:output rate increased by 33%and 47.02%and transportation rate increased by 25.43%and 9.51%,respectively.Dry matter accumulation was better in T1 and T9 treatments compared to the control CK treatment,with an increase of 27.72%and 5.10%,respectively.（4）The total nitrogen fertilizer utilization rate of mung bean plants in different treatments ranged from 34.75%to 47.71%,the total nitrogen fertilizer residue rate in0-15 cm soil ranged from 11.36%to 33.69%,and the loss rate ranged from 21.03%to53.89%,with the lowest total nitrogen fertilizer utilization rate and the highest loss rate in the T1 treatment with normal fertilization.（5）Nitrogen in all organs of mung bean plants was mainly derived from soil nitrogen.The accumulation of nitrogen fertilizer ¹⁵N in mung bean plants with different organic fertilizer with nitrogen fertilizer treatments ranged from 1.90 to 14.98 kg/hm² in root,1.73 to 6.88 kg/hm² in stem,2.77 to 10.09 kg/hm² in leaf,and 2.58 to 16 kg/hm² in pod.