上海都市型生态农业模式及对策

利用文献资料调查、统计分析和实地调研的方法, 分析总结了上海生态农业发展的现状, 研究提出了设施化+生态技术为主、集约化+生态技术为主、科技化+生态技术为主、市场化+生态技术为主、产业化+生态技术为主、观光休闲+生态技术为主等6个上海都市型生态农业发展的主要模式.重点分析整理了上海都市型生态农业的不同实践模式及其发展过程中存在的问题, 进而提出上海发展都市型生态农业的对策措施.     

Acidification of Solid and Solution Phases at Greater Depths (> 150 cm) at Solling Spruce Site

The acidification of the soil and percolation water at soildepths from 150 to 500 cm was studied at the Solling spruce sitefrom 1991 to 1996. NH₄Cl exchangeable cations of the fineearth and bedrock fractions were obtained from different depthsand the soil solution composition was monitored at 150, 200,300, 400 and 500 cm depths using seven suction lysimeters at each depth.In the seepage water collected from 150 and 200 cm depth, pHvalues decreased in the period 1991 to 1996, but no significantchanges were observed in solutions collected below 200 cm depth.Element budgets of Al and M_b (Na, K, Mg, Ca) cationsindicated that buffering by exchange of Al with M_b cationsoccurred mainly in surface 200 cm soil depth. High variabilities in concentrations of SO₄ (at 150 cm) andM_a (Al, Mn, H, Fe) cations (at 300 and 500 cm) wereobserved. High variabilities in M_a cations could beassigned to one of the lysimeters at each depththat extracted low pH solutions. The amount of exchangeablecations in the fine earth and the bedrock fractions indicatedthat the acidification front (exchangeable M_b cations < 80equivalent percent) had occurred to soil depth of more than 360cm, but the extent of acidification that might have occurred inthe preindustrial period is not known. In both fine earth andbedrock fractions, depthwise changes of exchangeable M_a andM_b cations were quite similar, suggesting that rockfractions have contributed to proton buffering not only bysilicate weathering but also by cation exchange.     

粉煤灰多元复混肥水稻配方研究

研究结果表明 ,施用粉煤灰多元复混肥 ,能增加土壤养分 ,满足水稻对多种营养元素的需求 ,促进水稻生长发育 ,提高水稻产量和经济效益。不同配方各处理产量与对照比均达到 1%显著差异。田间试验以 3∶1∶4和 3∶1∶2配方最佳 ,早、晚稻分别比对照增产 13.3%、10 .6 %和 10 .4 %、9.8%。