A quick method of soil moisture determination

Abstract

The method described here is useful for the quick determination of soil moisture, especially when many determinations are to be made at a time. The only pieces of apparatus required are some wide‐mouthed conical flasks, a few pieces of glass rod and a balance. The principle involves recording the weight of the flask filled with water and soil sample of known weight (A). This flask weight (H), and the predetermined soil particle density (D_p) and weight of the water‐filled flask (G) are then used to calculate moisture percentage (MP) in the soil sample from the formula:

The method was compared with conventional oven‐drying technique for a wide range of soil textures, moisture contents and other contrasting soil properties. The results obtained showed that the accuracy, precision and simplicity of the method are good, particularly for rapid practical uses.     

医药院校食品添加剂课程教学探讨

为满足现代社会对食品添加剂安全及使用的要求,培养学生具有合理选择、正确使用食品添加剂以及分析、解决实际问题的能力,对食品添加剂课程定位、教学内容和教学方法进行探索,以期提高食品添加剂课程教学质量.     

中等职业学校《机械基础》课程教学方法探讨

《机械基础》课程是中等职业学校机械类、机电类等专业的一门必修课程,具有知识面广、点多、内容抽象、实践性较强等特点,是较难掌握的一门课程。文章根据教学经验,针对《机械基础》课程教学方法提出了一些观点与看法,以其起到提高教学质量与效果的作用。     

Crown projection area of young Pinus sylvestris: A model and its test

In this study we applied a theoretical model for determining the projection area of a Scots pine (Pinus sylvestris L.) crown in different directions. The model is based on the assumption that the foliage elements (shoots) are randomly distributed within a symmetrical crown envelope. The model was tested using photographically measured data for three young Scots pine crowns. The compatibility between calculated and measured values was satisfactory.     

《基础会计学》教学内容改革探讨

针对基础会计教学中的记账方法、记账凭证及日记账的设置等内容陈旧、落后问题进行了探讨,旨在删减、统一及规范会计的记账方法、记账凭证及日记账的设置,使会计核算内容更适应现代市场经济的发展,尽快与国际接轨.     

J-80A型轮式集材拖拉机底盘的保养和调整方法

介绍了J-80A型轮式集材拖拉机底盘的保养和调整方法.     

中国饮茶方式的历史演进

中国饮茶方式历经了由唐以前的生煮羹饮、唐代的煎茶、宋代的点茶到明清瀹饮法的漫漫演进,中国饮茶方式的历史演变也是中华茶文化发展进程的缩影,也是中华茶文化的精华所在。     

小麦品种在低温下膜功能变化的生物物理学分析

本文以冬性及春小麦品种为试材，用示踪，液闪计数及测定电解质泄漏的方法，测定低温胁迫下膜脂的代谢和电解质渗透的变化，并根据热力学的原理，分析其生物膜上的化学反应和扩散过程及膜上物质通量Ｊｊ与跨膜电势Ｅｍ的函数关系。     

Effect of Egyptian cooking methods of faba beans on its nutritive value,dietary protein utilization and iron deficiency anemia 1. The role of main technological pretreatments

In order to study the effects of main technological pretreatments practised for preparing Egyptian faba bean products, i.e. decortication as well as soaking and germination followed by dehulling on the nutritional value, series of experiments were carried out. Such pretreatments had a significant effect on the changes in the chemical composition of faba beans. The proportion of the removed hulls reached generally about 14%. Data revealed also pronounced improvements on the nutritive value as a result of all studied pretreatments, especially germination being the most effective. Chemical scoring of all determined essential amino acids was >60, except methionine and cystine showed the lowest score (<20). Germinated seeds had the highest chemical score for the restricting amino acids beside the lowest GDR value [Grams consumed of product to cover the daily requirements for adult man in protein (63 g) and in energy (2900 kcal)]. All pretreatments caused a significant decrease in the antinutritional factors, especially soaking followed by dehulling, whereas decortication led to a significant increase in phytic acid content.     

反刍动物采食量的概念与研究方法

本研究对反刍家畜采食量的研究发展与现状进行了回顾与总结,采食量及其相关术语的定义主要基于饲草料或家畜,其测定方法和精确含义有差异;反刍家畜采食是由生物和非生物因素相互作用共同影响的复杂动态过程,采食量影响因子主要分为家畜的(胃肠蠕动力、选择性采食等)、饲草料的(粗纤维含量、抗营养成分等)和饲养条件的(草层结构、草地饮水点分布等)因素3个方面;采食量的测定方法有基于牧草测定的直接法和基于家畜测定的间接法,后者较多地应用于放牧家畜;预测方法有基于数学函数和生物学原理的模型法,基于消化试验的经验法和结合家畜属性的改进经验法。舍饲条件下可准确地测定和预测家畜的采食量,但对放牧家畜还没有精确的方法。通过测定与饲草水平密切相关的家畜尿液、血液或粪便中的代谢物水平将成为预测放牧家畜采食量的准确方法。