菏泽市定陶区系黄河中下游冲积平原,是农业大县,耕地面积6.2×104hm2,主要农作物以小麦、玉米为主.截至目前,全区农机总值达到6.1亿元;农机总动力达到8.6×105kW;大中型拖拉机保有量达到8688台,小麦联合收获机达到2066台,玉米联合收获机达1394台,农作物耕种收综合机械化水平达到92.2％.

采用雨养山药田间小区试验的方法,研究了稻草覆盖与化肥减量对山药生长、土壤温度和湿度的影响.结果表明,稻草覆盖还田既能明显降低高温时段(14:00)0～5 cm表土层的温度(平均降低1.5～2.4℃),又能明显提高高温干旱期0～5 cm表土层的水分保持能力(平均提高1.2～3.4个百分点),在稻草覆盖还田量相同条件下,化肥减量15％对0～5 cm表土层温度和湿度影响均不明显.由于稻草覆盖的降温保墒效应,山药成熟期产量和生物量均有所提高,分别增产1070～3490 kg/hm2和450～1780 kg/hm2,而在稻草覆盖还田量相同条件下,化肥减量15％则相反,分别减产1420～3615 kg/hm2和550～1368 kg/hm2.就土壤降温保墒和山药增产效应而言,可选择稻草覆盖量为4000～6000 kg/hm2条件下化肥减量15％.

The number of microbes and enzyme activity in Jatropha curcas L.planting soil and non-planting soil was investigated.The results indicated that the number of bacteria,actinobacteria and fungi in deep layer(20～50 cm) of the planting soil was larger than that in the superficial layer(0～20 cm);and the bacteria number of each layer,actinobacteria and fungi in non-planting soil was less than that in planting soil.The change of katalase activity in planting soil and non-planting soil was not obvious;and there was no significant difference between samples.The activity of urase,alkaline phosphatase and convertase was significantly different between samples from the same depth soil of planting and non-planting.

Field trials were conducted to study the effect of Silicon(Si) fertilizer application on the growth,yield and nutrient accumulation of early rice.Results showed that the application of Si fertilizer promoted the growth and increased the grain yield of rice significantly.Compared to NPK treatment,the dry matter amount of rice shoot in the treatment of NPK+Si increased by 4.1% and the grain yield increased by 6.2%.The key factors affecting the yield of rice were panicles and grain number per panicle.The panicles and grain number per panicle of rice in the treatment of NPK+Si increased by 12.1% and 19.2% respectively compared to that in NPK treatment.Results also showed that Silicon fertilizer application enhanced the fracture resistance force of the rice stem by 16.3% compared to that of NPK treatment.The results of nutrient accumulation showed that applying silicon fertilizer improved the accumulation of N,P and K by 15.7%,10.1% and 15.5% respectively.These results showed that the effect of silicon fertilizer application on early rice in double rice cropping regions of Southeast Hubei was significant.

农产品安全的危机 农产品质量安全问题是目前我国农业发展的一个主要矛盾。农药、兽药、饲料和添加剂、动植物激素等农资的使用,为农业生产和农产品数量的增长发挥了积极作用,也给农产品质量安全带来了隐患。据统计,我国部分省市上市蔬菜、水果农药污染超标率达20％左右,直接危害广大群众身体健康。