盐碱地农-渔开发对土壤环境的影响

在东北苏打盐碱地进行了稻-鱼-苇-蒲开发试验,并探讨了该模式对盐碱土壤环境的影响。结果表明,开发后土壤有机质含量增加96.8%(平均值,以下同),盐分含量下降43.6%,全量和速效N、P、K质量分数分别增加142.8%和188.2%;阳离子交换量、盐基总量分别增加8.21%及27.71%;土壤腐殖质以富里酸为主,w(HA)/w(FA)比值提高36.15%;养鱼稻田的土壤微生物总量明显高于未养鱼田(P<0.01);优势种为放线菌。土壤酶活性进一步加强。系统废水的盐分质量浓度降至1.0 g/L左右,碱浓度低于水源(7.0~10.0 mmol/L)。该模式不会造成土壤次生盐碱化。

Effects of coordination of farming and fishery on environment of soil in saline-alkaline land

Eco-agriculture pattern of rice-fish-reed-cattail was set up in soda saline-alkaline land of northeast China by means of fish culture in the paddy field, the reed pond and the cattail pond from 2000 to 2002, and the effects of this pattern on environment of saline-alkaline soil were studied. The results are as follows: (1)the increase rate of organic matter of soil is 56.2%~117.5% at after exploited, the decrease rate of salinity is 38.4%~47.8%, the content of total N, total P, total K, and available N, available P, and available K increase by 47.8%~253.3% and 60.7%~450.1%, respectively; (2)the increase rates of cation exchange capacity and exchangeable base are 6.31%~11.04% and 14.14%~43.54%, respectively; (3)the humus of soil take the fulvic acid as the dominant factor, the increase rate of HA/FA value is 21.08%~52.33%; (4)total amount of soil microbe in fish-rice ecosystem is higher than the ecosystem of normal rice farming (P<0.01), the dominant groups is actinomyces and bacteria, the molds is least, and enzyme activity of soil is taken further steps; (5)salinity and alkalinity of the wastewater decrease at 1.07~1.19 g/L and 7.07~10.13 mmol/L, respectively.