江西农田C、N、P、K平衡研究

江西省１９９７年农田Ｎ、Ｐ、Ｋ养分现状为：农田养分支出量为７４．３８３８×１０４ｔ、Ｐ２Ｏ５２１．８８７４×１０４ｔ、Ｋ２Ｏ４９．７５０１×１０４ｔ。其中粮食作物支出Ｎ占７３．９％，Ｐ２Ｏ５占７２．７％，Ｋ２Ｏ占７８．０％；投入农田养分Ｎ９０．６７×１０４ｔ，Ｐ２Ｏ５３２．９７×１０４ｔ，Ｋ２Ｏ４０．８×１０４ｔ，其中化肥Ｎ占７３．２０％，Ｐ２Ｏ５占８８．９０％，Ｋ２Ｏ占６０．５％，有机肥在农田钾素供应中仍占有重要地位；江西农田养分平衡状况，氮素有盈余（＋２１．９％），磷有较多盈余（＋５０．６％），钾则明显亏缺（－２１．９％）。江西农田有机质（Ｃ）平衡，估算江西有机质年分解量２２５３ｋｇ／ｈｍ２，年生成量５７６７ｋｇ／ｈｍ２，年生成量大于年分解量，土壤有机质出现积累。在综合分析现有资料基础上，提出了江西农田养分平衡允许率，Ｎ：－５．７％，Ｐ２Ｏ５：－３０％，Ｋ２Ｏ：－５４％。提出减磷、节氮，促进钾氮再循环的增效设想，和控制化肥用量，提高化肥肥效的建议，并提出实施的主要途径

Study on the Balance of C,N,P,K in Cropland of Jiangxi

In 1997, the balance situation of N, P, K in cropland of Jiangxi is as follows: in crop land the general output of N, P 2O 5, K 2O reached 74.3838×10 4t, 21.887 4×10 4t,and 49.750 1×10 4t respectively, of which 73.9%(N), 72.7%(P 2O 5) and 78.0%(K 2O) came from food crop land; while the input of N,P 2O 5, K 2O amounted to 90.67×10 4t,32.97×10 4t and 40.8×10 4t respectively, of which chemical fertilizer N, P 2O 5, K 2O made up 73.2%, 88.90%,60.5% respectively, organic fertilizer supplied quite a amount of K. Thus, cropland of Jiangxi had N surplus of 21.9%, P surplus of 50.6% and K lack of 21.9%. The balance of organic matter (C) in cropland of Jiangxi: it is estimated that the yearly decomposition quantity of organic matter is 2 253kg/hm 2, synthetic quantity is 5 767kg/hm 2, giving rise to a surplus of organic matter. (3) Comprehensive analysis of available material indicated that for cropland of Jiangxi, rational nutrient balace rate of N, P 2O 5 and K 2O should be 5.7%,30% and -54% respectively.