中亚热带三种母质发育的红壤对猪粪安全消纳量的初步研究

Maximum Safe Pig Manure Loading Capacity of Red Soils from Three Parent Materials in Mid-subtropical Region of China

采用盆栽试验方法,在自然降雨条件下模拟研究了中亚热带丘陵区3种母质红壤对猪粪的安全消纳能力。试验设在江西省鹰潭市余江县中国科学院红壤生态实验站,试验期间年均降水量为1 946 mm,年均温18.9℃。通过监测2012—2014年间土壤渗漏水氮磷迁移淋失,结合土壤养分含量和花生产量变化,初步确定3种母质红壤的猪粪安全消纳量。结果表明:常规化肥减半条件下,从NH4+-N、NO3–-N和总磷淋失对水环境影响,以及从土壤速效氮磷积累角度,红黏土、红砂岩和花岗岩红壤配施猪粪最大安全用量分别为P 100、50、50 kg/(hm2·a);从花生产量角度考虑持续配施猪粪施用量不宜超过P 100、200、200 kg/(hm2·a)。综合考虑经济效益和环境效益,红黏土、红砂岩和花岗岩,配施猪粪的最大安全消纳量分别为P 100、50、50 kg/(hm2·a),相当于施用鲜猪粪(含水量为69%)分别为24 000、12 000、12 000 kg/(hm2·a)。

A pot experiment under natural rainfall with three red soils developed on parental materials of red clay, sandstone and granite was investigated to estimate the maximum safe pig manure loading capacity in Ecological Experimental Station of Red Soil, Chinese Academy of Sciences. The research area represent a typical subtropical moist climate with a mean annual temperature of 18.9℃ and a rainfall of 1 946 mm. The maximum safe pig manure loading capacities of the three soils were estimated by monitoring NH4＋-N, NO3--N and total phosphorus in leaching water, the peanut production and the accumulation of available nutrients in the soil from 2012 to 2014. The results showed that the maximum safe application rate of pig manure was P 100 kg/（hm2.a） for red clay soil, and P 50 kg/（hm2.a） for sandstone and granite soils with half of conventional chemical fertilizers from the viewpoint of groundwater and soil environment protection. From the viewpoint of crop production, the safe application rate of pig manure should be no more than P 100 kg/（hm2.a）for red clay soil, and P 200 kg/（hm2.a） for sandstone and granite soils. Taking economic interests and environmental impacts into account, the maximum safe pig manure loading capacity could be P 100 kg/（hm2.a） for red clay soil, and P 50 kg/（hm2.a） for sandstone and granite soils with half of conventional chemical fertilizers, equivalent of 24 000 kg/（hm2.a） and 12 000 kg/（hm2.a） of fresh pig manure with moisture of 69%.