Revising Nitrogen Recommendations for Wheat in Response to the Need for Support of Variable-Rate Nitrogen Application

Sampling studies in North Dakota conducted from 1994 to 2003 showed that variable-rate N application could be practically directed with zone soil sampling. Results from variable-rate N studies using zone soil sampling were often less than rewarding due in part to the use of a whole-field predicted yield-based formula for developing the N recommendation in each zone. Nitrogen rate studies on spring wheat and durum were established in 2005 through 2009 with the objective to reexamine N recommendations and construct a new system if necessary. The results of the study and archived wheat N response data showed that the state should be divided into three separate N response regions. Within each region historic yields from low to high productivity were defined. The gross N rate was determined using the return-to-N concept developed in the US corn-belt states but with additional consideration for wheat protein value The gross N rate is then modified by credits for previous crop, soil test N from zone soil sampling, tillage systems, excessive straw from the previous year, relative susceptibility to nitrate leaching or denitrification. Finally, the user is encouraged to use common sense and consider whether particular fields have characteristics that require more or less N fertilizer than suggested by the recommendation formulas.     

菲律宾东达沃省木薯生产考察与发展建议

通过对菲律宾东达沃省木薯种植、生产条件和加工利用发展潜力实地考察,分析了当地木薯种植、生产与加工环节中存在的主要问题以及发展趋势,并对该地区木薯种植生产产业化发展提出若干建议。     

水稻缓控释肥肥效试验研究

以水稻为试验材料,通过对缓控释肥、配方肥和习惯施肥进行比较试验,研究了缓控释肥的肥料效应。结果表明,缓控释肥不但能够提高水稻的结实率和千粒重,而且能提高肥料利用率、偏生产力农学效率,节本增收效果显著。     

Efforts Toward Improving Maize Yields on Smallholder Farms in Uasin Gishu County,Kenya, through Site-specific,Soil-testing-based Fertiliser Recommendations: A Transdisciplinary Approach

This study evaluated the effects of site-specific, soil-testing-based fertiliser recommendations on maize yields using the transdisciplinary (TD) process. The TD process utilizes knowledge from science and practice. Farmers, extension officers, local financial institutions, and other practitioners collaborated with local scientists from the University of Eldoret in the process of financing, purchasing, and applying fertilisers in adequate amounts and composition. A total of 144 farmers participated in the study, which lasted for two seasons. The data sampling was based on a randomized 2?×?3?×?4?×?2 factorial complete block design, including the following factors: TD (non-participation vs participation in the TD process); ST (soil testing in the following categories: fertiliser application with no soil testing, fertiliser application following government recommendations, and application of site-specific, soil-testing-based fertiliser recommendations), and location (Kapyemit, Kipsomba, Ng’enyilel, and Ziwa). The “no soil testing” (ST₁) category refers to farmers’ own practices at an average fertilisation of about 60?kg?N?ha^?1 and 15?kg?P?ha^?1. The government recommendation (ST₂) calls for 75?kg?N?ha^?1, 25?kg?P?ha^?1, and 6?t?ha^?1 manure, and site-specific fertiliser recommendations (ST₃) were based on actual soil-testing results; generally, this resulted in the recommendation of 90?kg?N?ha^?1, 30?kg?P?ha^?1, 25 kg K ha^?1, 2?t?ha^?1 lime, and 1?t?ha^?1 manure. Highly significant effects were seen where farmers participated in the TD process (TD) for soil testing (ST). The farmers’ yields in Uasin Gishu County of 4.5?t?ha^?1 increased by approximately 1.5?t?ha^?1 based on site-specific, soil-testing fertilisation recommendations and by approximately 1.0?t?ha^?1 based on participation in the transdisciplinary process. However, as indicated by a significant interaction of the variables ST and TD—and while there is a significant main effect of participating in a TD process—the latter increase occurs only if site-specific, soil-testing-based recommendations can be used in the transdisciplinary process with farmers.     

A literature review of reports of the stability and storage of common injectable chemotherapy agents used in veterinary patients

Many chemotherapy drugs used in human patients are discarded after single use or within 24 h of reconstitution, as per the manufacturer's product label recommendations. This can be wasteful and costly to veterinary clients. This report reviews the published stability and storage data for 19 injectable chemotherapy drugs commonly used in veterinary medicine. Based on these data, storage procedures are presented, assuming aseptic technique and a closed system drug transfer device (CSDTD) are used for drug preparation and handling. Further studies on the risk of microbiological contamination of chemotherapeutics using a CSDTD, and validated high quality drug assays such as stability‐indicating high‐performance liquid chromatography, are required. The authors' intent is not to supersede product label recommendations, but to suggest that longer storage without significant loss of drug efficacy may be possible, thus reducing the costs of chemotherapeutics to some veterinary clients.     

滑准税对中国棉花市场影响的实证分析

摘 要：现行滑准税政策是我国加入WTO后棉花贸易政策的重要组成部分。本文首先回顾了国内有关专家学者就滑准税政策的研究结论,在此基础上就滑准税对棉价波动及进口量波动的影响、滑准税对国内棉花市场价格的影响以及滑准税对纺织业的影响进行了实证研究。最后,对现行滑准税改革提出政策建议。     

南京新优园林植物调查与应用分析

对南京各地进行实地调研,结合相关资料搜集,共统计新优园林植物151种,隶属69科134属。结果表明:南京新优园林植物应用存在乔、灌、草发展不平衡,以多年生草本和灌木为主体,且植物应用频度低等现象。并对发展中存在问题提出改进建议。     

规模养殖与畜牧业机械化发展

从畜牧业机械化发展的一般规律和养殖规模与畜牧业机械化发展的关系入手,分析了当前我国不同养殖规模畜牧业机械化发展进程及主要存在的问题,提出针对不同养殖规模畜牧业机械化发展的政策建议。     

生态农业技术推广的分析与建议

我国属于农业大国,在农业生产的发展过程中,农业占据着相当重要的位置。本文将对生态 农业的概念、意义以及为何要发展生态农业和当前生态农业技术推广过程中存在的一些问题进行简 单阐述与分析,并针对加强生态农业技术推广提出几点建议,寄望能给相关业界提供有价值的参考。     

POLICIES AND REGULATIONS FOR PROMOTING MANURE MANAGEMENT FOR SUSTAINABLE LIVESTOCK PRODUCTION IN CHINA: A REVIEW

• Manure utilization is hindered by separate specialist crop and livestock production systems. • Improving manure utilization requires organizations for manure exchange. • Policies and action plans for improving manure utilization are critically reviewed. • A manure chain approach with third-party contractors is recommended. Livestock numbers in China have more than tripled between 1980 and 2017. The increase in the number of intensive livestock production systems has created the challenges of decoupled crop and livestock systems, low utilization of manures in croplands, and subsequent environmental pollution. Correspondingly, the government has enacted a series of policies and regulations to increase the sustainability of livestock production. This paper reviews the objectives of these policies and regulations and their impacts on manure management. Since 2017 there have been two policy guides to speed up the appropriate use of manures, three action plans for increasing manure recycling, and one technical guide to calculate nutrient balances. Requirements of manure pollution control and recycling for improved environmental performance of livestock production systems were included in three revised environmental laws. Most recent survey data indicate that the utilization of livestock manures was 70% in 2017, including that used as fertilizer and/or for production of energy. The targets for manure utilization are 75% in 2020 and 90% in 2035. To achieve these targets and promote ‘green livestock production’, additional changes are needed including the use of third-party enterprises that facilitate manure exchange between farms and a more integrated manure nutrient management approach.