关于安塞区林业发展的几点建议

安塞区通过近些年来各项林业重点工程的实施,生态环境有了明显改善,但也存在一些问题,为加快安塞林业高质量发展,特提出几点合理化建议     

河南彩色乔木植物新资源调查研究

首次对河南彩叶木本植物种、变种、品种资源进行了全面调查研究。调查结果表明,河南木本彩叶植物(种、变种、变型、品种)逾150种。现对其中54个新记录植物的形态特征和产地进行了介绍,并且分析了彩叶树木新植物的开发利用价值,以期丰富河南省园林绿化树种。     

环境保护工作中开展污染企业信用评级的探讨

通过对现有环境保护工作中污染企业风险事件管理的现状分析,对污染企业信用评级的概念、内涵、模式进行了研究,探讨了开展污染企业信用评级的可能性,并就相关技术问题进行了讨论,提出了在污染企业开展信用评级的政策性建议。     

客土喷播的护坡机理及基材和施工等控制要点

针对许多的岩质边坡,工程防护与周围环境极不协调;而植被护坡既缺少植物生长的土壤基础,又忽略边坡防护效果。客土喷播在一定程度上解决这一矛盾,本文对比分析客土喷播的护坡机理,详细地介绍基材及其要求,对其施工工艺等方面也做了全面阐述,对目前研究过程中存在的几个问题提出针对性的建议。期望推动客土喷播的研究不断深入和发展,促进客土喷播理论和技术上都更加成熟。     

Grouping Soils by Taxonomic Order to Improve Lime Recommendations

The success of a liming program is dependent upon the accuracy of the lime recommendation, which in turn depends on the quality of the underlying correlations and calibrations. Because of the expense, large-scale field calibration experiments are rarely conducted. The relatively low economic returns from pastures make it even more unlikely that a calibration experiment would be conducted, especially in West Virginia. Therefore, any improvements in lime recommendations have to be made from lime correlations. Moreover, it is unlikely that a single lime correlation can accurately identify appropriate lime rates for all soils. Hence, the objectives of this study were to improve the accuracy of lime recommendations by using quick tests that account for soil order and to develop lime correlations for acidic pasture soils of West Virginia. Twenty-five surface soil samples (0–7.5 cm) from the three major soil orders in the state (Alfisols, Inceptisols, Ultisols) were collected, most in cooperation with state soil scientists. Standard procedures for the determination of lime requirements by the Adams–Evans buffer (AEB), Mehlich single buffer (MB), and Shoemaker–McLean–Pratt single buffer methods (SMPB) were used. Statistically significant improvements in lime recommendations for target pH values of 6.5 and 5.5 were achieved by accounting for soil order. Mehlich single buffer recommendations were better for Alfisols and Ultisols than for Entisols to achieve pH 6.5. Lime correlations were developed for all three chemical buffers by multiple regression where the independent variables were target pH and soil-buffer pH. The AEB predicted lime rates better for target pH 5.5.     

Exchangeable K levels for maximum crop yields on soils of different cation exchange capacities

Abstract

Wide differences in levels of exchangeable K considered adequate for maximum yields in different States are probably a consequence of the acceptance of either a single 200 pp2m rate for 95–987. sufficiency suggested by Bray, or a variable level based on a percentage of the soil cation exchange capacity (CEC) proposed by Bear. It now appears that sufficiency levels should vary with soil CEC, but not merely as a simple percentage of it. Moreover, the relatiorshlp in practice is complicated by such factors as leaching of K from coarse textured soils, and fixation of added K in, and release of native K from, non‐exchangeable forms in soils high in micaceous clay content. Since these influences occur widely in Ohio soils, the need for new field studies was recognized and implemented. Laboratory and growth chamber studies relating K sufficiency to energies of exchange were examined. Also, a new procedure used by the Ohio Soil Testing Laboratory for providing K sufficiency baaed on soil CEC and crop yield and composition is described.     

Improved SMP buffer method for determining lime requirements of acid soils

Abstract

Single buffer‐two pH and two‐buffer adaptations were compared as double buffer features of the SMP method using a group of 54 soils of wide range in lime requirement (LR). Data from both methods were highly correlated both with each other and with Ca(OH)₂‐titrated acidity.

Formulas for LR based on the schematics of similar triangles relating differences in measured pH vs corresponding acidities for the double buffer system were developed. A regression equation relating buffer‐indicated LR and Ca(OH)₂ titrated acidity was used to adjust the quick‐test double buffer‐indicated values to levels nearer the actual ones. A recommended SMP double buffer procedure, and a formula for computing LR from soil‐buffer pH's measured by the double buffer, quick‐test method are presented.     

Relationship between minimum exchangeable potassium and soil taxonomy

Abstract

Potassium is an essential element for plant growth and its importance in agriculture has been well recognized. With continuous cropping of a soil, exchangeable ? levels decrease to a minimum, steady‐state level if no ? is added. This minimum level is important to both modeling soil ? cycling and fertilizer ? recommendations, and it has been determined by field studies lasting from 2 to 10 years. Consequently, there is a need for estimation of minimum exchangeable ? levels for a wide range of soil types from soil physical and chemical properties. A literature survey provided 19 studies where minimum exchangeable ? had been measured and regression analysis was conducted on this data to determine predictive relationships. Minimum exchangeable ? is closely related to soil clay content (r² from 0.66 to 0.99), however, regression constants varied from study to study. Improved correlations were obtained between minimum exchangeable ? and clay content when all the soils (22A, r²=0.69) were divided into 3 groups according to the Fertility Capability Soil Classification (FCC) System and Soil Taxonomy (r² of 0.86, 0.82, and 0.68). Differences in regression constants between groups were consistent with changes in soil properties associated with ? levels and exchangeability. This analysis provided relationships to estimate minimium exchangeable ? level from soil clay content for a wide range of soil types, which should aid soil ? modeling and fertilizer ? recommendations.     

NO3‐N Soil Test—approaches to use and interpretation

Abstract

Nitrate‐nitrogen (NO₃‐N) soil tests have been instituted by several Great Plains States to aid in making nitrogen fertilizer recommendations. The NO₃‐N soil test is useful in the Great Plains because climatic conditions are such that NO₃‐N leaching is low and soil rooting depths are great.

Essentially four basic approaches to the use and interpretation of the NO₃‐N soil test have been developed and are discussed. They are: (1) total amount of NO₃‐N extracted from a two foot soil profile is available to the growing crop; (2) only a portion of the extractable NO₃‐N is available to the growing crop; (3) other mineral nitrogen, such as NH₄‐N, is just as available to the growing crop and (4) some nitrogen becomes available from the soil organic matter. The NO₃‐N soil test requires that deep samples (two feet or more) be taken and that they are air‐dried as rapidly as possible. Late fall or early spring soil samples are necessary for interpretation of the NO₃‐N soil test.     

试论我国农机企业发展现状与对策

我国是世界第二大农机制造国,也是世界最重要的农机市场之一。农机企业是农业机械发展的主体,本文分析了我国农机企业的发展现状并提出相关建议,以期为我国农机行业健康快速发展提供借鉴。