| Recently,livestock and poultry breeding in China have increased rapidly.The nutrient amount from livestock and poultry manures had reached 9.74×10~7 kg N/a and 2.67×10~7 kg P/a in Beijing,Hebei,Henan,Shandong.It has been showed in farmers' investigation that manure types,amount and application measurements for crops differed greatly by different farmers.In North China in summer there is rich rainfall,frequently heavy rain. When manure application succeeded with heavy rain,it might induce nutrient loses.Up to now,however,few works were done about impacts of manure types,amount and application measurements on nitrogen and phosphorus losses of cropland in the region.In order to understand N and P losses from manure application of crop land,experiments were carried out in Langfang research station in 2008.Methods of artificial rainfall simulation was involved.With 26 treatments,N and P losses through runoff and leach procedures from crop growing field were studied.The treatments included two manure application measurements(surface application and plowing application),manure amounts in 3 P-levels and 4 manure sorts.The main results were as follows:1.Under 160 mm rainfall simulation,the amount of surface runoff water and leakage water were not different significant,with 48.64%and 44.90%of the rainfall respectively. The results of 13 experiments showed for runoff,the outflow lasting time after rainfall stopping is only 1/5 of that of leakage,with the average of 3.36 minutes and 16.75 minutes respectively,but the velocity of runoff is 1.5 times faster than of that of leakage, with the average of 71.97 mL/min and 48.43 mL/min respectively.2.Under 3 manure amounts application judged by P -level,for surface runoff,the total P losses were different significant with 1.02,3.86 and 6.66 kg P/hm~2 respectively,the total P concentrations of runoff water were not different significant,with 0.17,0.73,1.92 mg P/L respectively;for leakage the total P losses were different significant with 0.77,3.03 and 12.12 kg P/hm~2 respectively,the total P concentration of leakage water were different significant,with 0.30,1.03,2.73 mg P/L respectively.The N amount of the three application could be classed to 3 level,with 0,＜500 kgN/hm~2 (220～440 kg N/hm~2) and＞500 kg N/hm~2(660～1320 kg N/hm~2),for surface runoff, the total N losses were not different significant with 4.89,12.75 and 23.6 kg N/hm~2 respectively,the total dissolved nitrogen concentration of runoff water were different significant,with 0.81,2.3 and 5.62 mg N/L respectively;for leakage the average total N lose were not different significant with 20.99,38.56 and 51.02 kg N/hm~2 respectively.3.Under the manure application amounts 0～320 Tg·/hm~2,with two application measurements:surface application and plowing application,the runoff total P losing were different significant,with 7.92 kg P/hm~2和2.6 kg P/hm~2 respectively,the leakage total P losing were different significant,with 11.97 kg P/hm~2和5.19 kg P/hm~2 respectively, the total N lose were not different significant,the runoff lose were 45.42 kg N/hm~2 respectively,the leakage lose were 44.16 kg N/hm~2 respectively.4.Under the condition of P amounts 75 kg P/hm~2,for surface application,the total P losses of runoff with cattle manure,pig manure,chicken manure were 5.20,3.41 and 5.43 kg P/hm~2 respectively,total N losses were 11.02,47.19 and13.79 kg P/hm~2 respectively, the total P losses of leakage were 7.03,2.70 and 2.92 kg P/hm~2 respectively,total N losses were 23.6,56.88 and 34.99 kg N/hm~2 respectively;for plowing application,the total P lose of runoff with cattle manure,pig manure,chicken manure were 2.18,1.89 and 2.43 kg P/hm~2 respectively,total N lose were 3.74,15.34 and 10.83 kg N/hm~2 respectively,the total P lose of leakage were 6.48,3.03 and 3.14 kg P/hm~2 respectively,total N lose were 35.57,45.37 and 64.66 kg N/hm~2 respectively.Under the condition of P amounts 225 kg P/hm~2,for surface application,the total P losses of runoff with cattle manure,pig manure,chicken manure were 13.28,8.28 and9.17 kg P/hm~2 respectively,total N losses were 18.05,22.47 and 22.95 kg N/hm~2 respectively,the total P losses of leakage were 18.51,13.55 and 22.17 kg P/hm~2 respectively,total N losses were 42.84,54.52 and 59.71 kg N/hm~2 respectively;for plowing application,the total P losses of runoff with cattle manure,pig manure,chicken manure were 3.91,2.47 and 2.86 kg P/hm~2 respectively,total N losses were 14.17,20.71 and 17.81 kg N/hm~2 respectively, the total P losses of leakage were 6.27,5.12 and 7.08 kg P/hm~2 respectively,total N losses were 29.71,58.50 and 31.17 kg N/hm~2 respectively.Based on the results obtained,for organic fertilizer there is more environmental risk by surface application compare with plowing application.With the organic fertilizer application amount 0～320 Tg/hm~2,there would be twice total P losses for surface application compared with plowing application in despite of runoff or leakage.Under the condition of big amount manure application,the leakage P losses were very heavy,it could be as high as 12.12 kg P/hm~2 twice that of runoff losses.This study also show that, in North China,the runoff by heavy rain or the leakage by continuous rainfall both cause the nitrogen and phosphorus lose of farm field,result in agricultural non-point source pollution.
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