核桃—小麦间作土壤养分与酶活性的变化

研究核桃—小麦间作土壤养分和酶活性的变化.结果表明,与单作小麦土壤相比,核桃—小麦间作对土壤理化性质有一定的影响,主要表现为土壤有机质丰富,并随种植年限的增加呈上升趋势;土壤中速效磷的含量开始没有明显变化,但是经过一段时间后其含量逐渐上升;全氮量随年限的增加先下降后上升.说明经过较长时间的核桃—小麦间作对土壤中氮、磷有...     

不同覆盖措施的保水效果及对烟叶产质的影响

在大田条件下研究了不同覆盖保水措施对烤烟生长发育、土壤含水量、烟叶产质及病害发生的影响。结果表明,地膜覆盖和秸秆覆盖均可显著促进烤烟的生长发育,其中地膜覆盖对烟株早期生长有利,而秸秆覆盖在烟叶旺长后优于地膜覆盖;两种覆盖方式均可增加干旱季节各土层土壤含水量,减少土壤水分蒸发,但前期地膜覆盖的保水效果优于秸秆覆盖;覆盖栽培有利于减轻烟草花叶病的发生;可显著提高烟叶产量和上等烟比例,其中以秸秆覆盖表现更佳。     

治理沈阳市镉污染土壤前景效益分析

沈阳是一个重工业城市，工业“三废”排放量很大，特别是污灌区，由于污水中含有大量污染物，随着污灌年限加长而导致土壤重金属污染不断加重，进而威胁到广大城乡人民群众的身体健康。治理被污染的土壤不仅能获得良好的经济效益，更具有深远的社会效益和环境效益。     

伊河川区温棚蔬菜土壤连作障碍及解决对策

一、土壤连作障碍产生的原因(一)土壤养分比例失调在温棚蔬菜生产中一般菜农只重视氮磷等大量元素,而忽视其他微量元素的投入。由于连年种植会造成蔬菜对某些元素的吸收较多,而对其他元素吸收相对较少,破坏了土壤的营养平衡,久而久之,造成土壤养分比例失调。(二)土壤反应异常由     

施用硼肥促棉花优质高产

硼是棉花生长和开花结实过程中必不可少的微量元素．土壤缺硼会严重影响棉花的产量和品质。土壤缺硼时．在氮、磷、钾等营养元素充足的条件下．增施优质硼肥，棉花增产可达15％～20％。     

毫州市土壤地力水平状况及培肥施肥对策

1土壤地力水平状况 1 1地力水平有所提高测定结果为：土壤有机质平均含量L.47％．全氮含量0．11％．碱梓氮75．9mg／kg五氧化二磷为25．1mg／kg，氧化钾为183．3mg／kg，参考《安徽省平原砂姜黑土、潮土耕地类型区耕地土壤地力等级定级体系与结果》养分含量指标，综合分析得知：我市土壤养分水平有机质逐年提高，达到中等偏上，平氯，高磷，中等佩高钾。     

复合生物钾肥在蔬菜上的使用效果综述

复合生物钾肥是中国农业科学院土壤肥料研究所与北京中农新科生物科技有限公司联合研制生产的新型微生物肥料。产品中含多种有益微生物及其衍生的具有独特作用机理的有效功能成份,复合生物钾肥利用现代生物技术防治土传病害、提高农作物生长活力、改良土壤结构和土壤微生态环境     

Effects of Magnesium Compound with Fertilizer on Daylily （Hemerocallis citrina Baroni） Growth and Soil Nutrients

Effects of two kinds of magnesium compound with fertilizer on Daylily （Hemerocallis citrina Baroni） growth, yield, and soil nutrients in red soil were studied. The results indicated that significant effects of magnesium applied to soils were observed in increasing Daylily （Hemerocallis citrina Baroni） yield, improving its growth, and strengthening its antivirus property as well as increasing the amount of exchangeable Mg, N, P, and K in red soil. In particular, the effects of magnesium compound fertilizer Ⅱ （MCF2） with higher Mg content were better than that of the others, which increased Daylily （Hemerocallis citrina Baroni） yield by 57.4, 32.8, and 14.5% compared to that of control treatment （CK）, chemical fertilizer with nitrogen, phosphorus, potassium treatment （CF）, and magnesium compound fertilizer Ⅰ treatment （MCF1） with lower Mg content. It increased soil Alkali N, available P, exchangeable K, and exchangeable Mg by 94.9, 46.5, 31.1, and 35.3%, respectively, compared with that of CK treatment. Therefore, the application of magnesium compound with fertilizer is an optimum method for improving red soil quality.     

Purification of Two Antimicrobial Substances Produced by Bacillus subtilis Strain B11 and Their Properties

Two antimicrobial substances produced by Bacillus subtilis strain B 11 were purified by boiling, DEAE 52 anion exchange chromatography and aluminum oxide adsorption chromatography, These purified substances showed only one spot on silica gel thin layer chromatography （TLC）. Antimicrobial assays showed that antimicrobial substances A and B inhibited the growth of plant pathogens such as Fusarium oxysporum Schl f.sp. niveum, Rhizoctonia solani, Ralstonia solanacearum and Xanthomonas oryzae pv. oryzae. In addition, antimicrobial substance B could also inhibit the growth of Magnaporthe grisea. These two antimicrobial substances were resistant to proteolytic enzymes and temperature as high as 121℃.