有機栽培における施用有機質堆肥の窒素と炭素の作物吸収,土壌残存、揮散等の動態解析

近年来，人们重新认识到畜禽粪便对农业生态系统的重要性，并利用~（13）<13>C和~（13）<15>N标记的畜禽粪便研究了其氮素动力学，以掌握畜禽粪便的最佳施用方法。通过这些研究揭示了各种作物对来自动物粪便的氮的吸收率。^<13>C和^<15>N标记肥料的生产。<13>在<15>玻璃温室中，用（~ <15>2NH_4）_2SO_4、K_2NO_3<15>（~ 2N各约10 <15>atom%_2）和~ 2CO_2<13>培养碳、~ 2N标记马齿玉米。收获后，将马齿玉米用焦炭饲料粉碎机粉碎，青贮约2个月作为奶牛饲料，每天收集1头体重约150 kg的奶牛<15>粪便，每天收集1 ~ 1 N标记的牛粪便，连续2天，每天收集1 ~ <13>1C和1 ~ 1 <15>N标记的牛粪便，连续3天。通过添加水和木屑，这些牛粪的水分和C/N比分别约为65%和40。将0.5kg左右的物料在50℃的聚苯乙烯泡沫塑料箱中堆肥3个月，堆肥过程中有时将粪便混合以促进堆肥，当粪便干燥时加水。结果，获得了~ <13>1C-和~ 1 <15>N-标记的粪肥堆肥。水稻直接吸收的<13>碳和氮<15>占堆肥总量的1%~ 2%，<13>玉米直接吸收的碳占堆肥总量的10%~ 13%。

Recently, animal manure was rediscovered as being significant to agricultural ecosystems, and the nitrogen kinetics have been studied with ^<13>C and ^<15>N labelled manure to grasp the optimum methods of animal manure appolication. The uptake ratios of nitrogen derived from animal manures on various crops were revealed through those studies.Production of ^<13>C and ^<15>N labelled manure.^<13>C and ^<15>N-labelled dent corn was cultivated in glass house by applying (^<15>NH_4)_2SO_4 and K^<15>NO_3 (about 10 atom% ^<15>N each) and ^<13>CO_2. After harvesting, dent corn was broken into pieces with a cokefodder crusher and silaged for about 2 moths as cow feed.A cow (about 150 kg weight) was fed with ^<15>N-labelled cattle feces was collected daily for 2 dags, and ^<13>C and ^<15>N-labelled were collected daily for days. By addition of water and sawdust to them, moisture and C/N ratio of those cattle feces became about 65% and 40, respectively. About 0.5kg of the materials were composted in a styrofoam box at 50℃ for 3 months.The manure was sometimes mixed to promote the composting, and water was added when the manure was dried up during the composting period. As a result, ^<13>C-and ^<15>N-labelled manure composts were obtained. From 1 to 2% of the ^<13>C and ^<15>N in the compost were absorbed directly by rice plant and from 10 to 13 of the ^<13>C in the compost were absorbed directly by dent corn plant.