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山东禹城和湖南桃源是位于我国不同地区均以种养生产为主的两个县(市),根据养分平衡原理对这两个县级区域尺度的农田系统氮、磷收支状况进行了计算分析,结果表明:自1980年以来,单位面积耕地上氮磷的输入量与输出量均表现为不断增加,但是,因为输入增长高于输出增长,导致农田系统产生较多氮磷养分盈余,两个地区存在明显差异。禹城农田系统氮磷盈余量呈逐年增长趋势,氮盈余量从133.8 kgN.hm-2增加到目前的450 kgN.hm-2以上,磷盈余量从6.2 kgP2O5.hm-2增加到目前的148.9 kgP2O5.hm-2;在其11个乡镇中有10个表现为氮盈余、9个表现为磷盈余,其中氮盈余量最多的高达841.8 kgN.hm-2,磷盈余量最多的达到297.8 kgP2O5.hm-2。桃源农田系统氮磷盈余量表现为先增后降,氮盈余量从100 kgN.hm-2左右增加到2002年达到峰值253.7 kgN.hm-2后,逐渐下降到目前的150.0 kgN.hm-2左右,磷盈余量从20.0 kgP2O5.hm-2左右增加到2002年的峰值95.9 kgP2O5.hm-2后,下降到目前的34.4 kgP2O5.hm-2;在其40个乡镇中有36个表现为氮盈余、26个表现为磷盈余,其中氮盈余量最高的达到561.7 kgN.hm-2,磷盈余量最高的为171.1 kgP2O5.hm-2。农田系统氮磷养分大量盈余主要是源于投入化肥量和承载粪便量较高,山东禹城明显高于湖南桃源,所以,为了减少养分盈余损失,应根据农田作物生长养分需求尽可能地减少化肥投入,并根据耕地粪便承载容量在区域内外合理调配畜禽粪便的施用。
Shandong Yucheng and Hunan Taoyuan are two counties (cities) located in different areas of China, mainly planting and breeding production. According to the principle of nutrient balance, the balance of farmland system nitrogen and phosphorus balance at the two county-level scales was calculated The results show that since 1980, the input and output of nitrogen and phosphorus per unit area of cultivated land all show an increasing trend, but because the input growth is higher than the output growth, resulting in more nitrogen and phosphorus nutrient surplus in farmland system, two There are obvious differences between the regions. The surplus of nitrogen and phosphorous in Yucheng farmland system showed an increasing trend year by year. The nitrogen surplus increased from 133.8 kgN.hm-2 to the present 450 kgN.hm-2 and the phosphorus surplus increased from 6.2 kgP2O5.hm-2 to 148.9 kgP2O5.hm-2. Of the 11 townships, 10 showed nitrogen surpluses and 9 showed phosphorus surpluses. Among them, nitrogen surpluses were up to 841.8 kgN.hm-2 and phosphor surpluses up to 297.8 kgP2O5. hm-2. The surplus of nitrogen and phosphorus in farmland system of Taoyuan increased firstly and then decreased, and the surplus of nitrogen increased from about 100 kgN.hm-2 to about 253.7 kgN.hm-2 in 2002, then gradually decreased to the present 150.0 kgN.hm-2 Phosphorus surpluses decreased from about 20.0 kgP2O5.hm-2 to about 95.4 kgP2O5.hm-2 in 2002, down to the current level of 34.4 kgP2O5.hm-2. Of the 40 townships, 36 showed nitrogen Surplus, 26 showed phosphorus surpluses, with the highest nitrogen surplus reaching 561.7 kgN.hm-2 and the highest phosphorus surpluses being 171.1 kgP2O5.hm-2. Large surplus of N and P nutrients in farmland system was mainly due to the higher input of fertilizer and carrying manure, Shandong Yucheng was significantly higher than that of Hunan Taoyuan. Therefore, in order to reduce the loss of nutrient surplus, fertilizer should be reduced as much as possible according to the crop nutrient requirements Input, and according to the carrying capacity of arable land in the region and outside the reasonable deployment of livestock manure application.