Effects of Carbofuran on Availability of Macronutrients and Growth of Tomato Plants in Natural Soils and Soils Amended with Inorganic Fertilizers and Vermicompost

The effects of lower field rate (LFR), field rate (FR), and higher field rate (HFR) applications of carbofuran on ammonium (NH₄)-nitrogen (N), nitrate (NO₃)-N, available phosphorus (P), and available potassium (K) contents in natural soils and those amended with inorganic fertilizers and vermicompost on the growth of tomato plants were studied. The NH₄-N, NO₃-N, available P, and available K contents increased up to FR but the most significant increase in was observed at LFR of carbofuran application. At HFR there was a significant reduction in nutrient availability. With passage of time all these parameters increase up to 30 days; thereafter, a decrease was observed up to the end of the experiment in both unamended and amended soils. The greater plant growth was observed at LFR of carbofuran application and at HFR the plants exhibited phytotoxicity in the form of marginal leaf scorching in both systems. The morphological growth parameters of tomato plants were positively correlated with nutrients availability.     

锌的消化吸收机制研究进展

介绍了不同锌源的消化吸收特点、锌的吸收机制、分布和调节等方面的研究进展，为进一步研究锌的吸收及其在动物生产中的合理利用提供参考依据。     

植物组织培养中有机添加物应用研究

植物组织培养中,在培养基内加入有机添加物,对培养物的分化、增殖有明显促进作用。文章综述了有机添加物的作用及其目前在植物组织培养中的应用情况。     

有机认证新标准的解析及对我国有机蔬菜产业的影响

最近发布实施的有机产品认证新标准对有机产品认证提出了更加严格的要求。通过对新标准的解析,系统阐述了新标准对有机蔬菜在生产资料选择、生产过程中的轮作、产品的检测、销售和质量追溯体系建立等方面的要求,分析了新标准对今后我国有机蔬菜产业发展的影响。     

菌丝生长速度与呼吸消耗及胞外酶活性的关系

以棉籽壳为主料,对平菇、刺芹侧耳、黄伞、灵芝、金针菇和香菇原种培养期间的菌丝生长速度、呼吸消耗及胞外酶活性的关系进行了研究。结果表明,6种食用菌的菌丝生长速度与呼吸消耗正相关,而有机物的降解速率与胞外酶活性的大小没有相关性。     

32P distribution in white radish roots at various fertilization rates

Abstract

The uptake and distribution of ³²P from labelled monocalcium phosphate by white radish (Raphanus Sativus) roots at five phosphorus fertilization rates were studied.

After on initial period of degradation (approximately 6 weeks), there is a sharp decline of phosphorus uptake. Graphical representation in Tables and Figures of the phosphorus distribution is presented.     

Root Exudates of Rice Cultivars Affect Rhizospheric Phosphorus Dynamics in Soils with Different Phosphorus Statuses

Exudation of organic acids by the roots of three rice cultivars grown in three soils of different phosphorus (P) statuses, and their impacts on the rhizospheric P dynamics and P uptake by the rice plants, were investigated. Quantum root exudates from all the rice cultivars were significantly greater at 21 days after transplantation than at panicle initiation or flowering stages. Malic acid was the most predominant organic acid present in the rice root exudates (10.3 to 89.5 μmol plant^?1 d^?1), followed by tartaric, citric, and acetic acids. Greater exudation of organic acids from rice grown in P-deficient soil by all the rice cultivars suggested response of rice plant to P stress. Results indicate that the release of organic acids in the root exudates of rice plants can extract P from strongly adsorbed soil P fraction, thereby increasing native soil P utilization efficiency and ensuring adequate P nutrition for the growing rice plants.     

Soil tillage for crop production and for protection of soil and environmental quality: a Scandinavian viewpoint

Based on experience from 35 years of tillage research in Sweden, future development of soil tillage is discussed and some research problems are identified. Tillage and seeding methods must be more carefully adapted to conditions at individual sites and occasions. Low-pressure typres, better weed control and improved seed coulters favour the increased use of reduced tillage. In order to diminish the impact of agriculture on the environment, it is necessary to develop methods for establishment of crops in the early spring or immediately after harvest, even in soils with large amounts of crop residues or high moisture content. The roles of tillage methods, and of soil compaction and structure on environmental impact of agriculture must be investigated. World food production must increase, since the world population is rapidly increasing. Therefore, it is necessary to develop improved crop production systems, including crop establishment systems, which favour efficient use of basic crop growth factors, while protecting or increasing soil productivity. Compaction, decreased organic matter content, and erosion are important long-term threats to soil productivity.     

6种牧草产量对有机肥SustainGro的响应

随着我国有机畜牧业的兴起,有机饲草的生产也迫在眉睫。本试验试图探讨有机肥对牧草产量的影响,结果表明有机肥SG不但能提高牧草产量,而且还能增加收益,随施肥量从450～900kg/hm2的增加牧草产量也不断增加,与对照相比施有机肥后苜蓿收益可增加216～710元/公顷。     

丹麦有机猪的生产和养猪业沙门氏菌的控制

本文介绍了丹麦有机猪的生产情况(有机猪的品种、畜舍环境和条件、畜舍卫生和饲养饲料状况)、沙门氏菌控制计划的情况(饲料、种猪群、断奶仔猪群、育肥猪群和屠宰场的监控)和效果。同时,简析了我国发展有机畜牧业的必要性,最后提出实行危害分析和关键控制点(HACCP)预防管理体系和有机养殖是我国养猪业的发展方向。