Excerpt from A Recording Soil Moisture Tensiometer The simple - design recorder can be built with readily available materials in a shop equipped with wood and metal working equipment by anyone familiar with these tools. It is composed of four basic sys tems: (l) the porous cup and re lated tubing; (2) the manometer, scale, and mercury storage cup; (3) the float-and-lever system and pen; and (4) the chart drum and drive. These systems are mounted on a plywood and plastic base. The porous cup (fig. 2) is placed in the soil at the desired depth, and the transfer of water through the cup changes the water volume in the manometer system. Two small nylon tubes extend to the soil surface and connect the porous cup to a flushing tube and the recorder. The connecting tubing is cut to lengths suitable to the particular installation. The flushing tube is used primarily to fill the porous cup and balance the manometer system. The recorder tube is sealed to the top of the glass manometer at the recorder. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Excerpt from Soil Moisture: A Record of the Amount of Water Contained in Soils During the Month of June, 1895 The records showing the conditions in the West are all commented upon directly under the diagrams. AS a rule, during th1s favorable season the fields under ordinary cultivation and those which had been subsoiled and subsequently cultivated do not Show very different mois ture conditions. In some places the-effect of cultivation is not appar ent upon the moisture content of Soils. For reasons which have already been, given it is not to be expected that cultivation would Show a very marked effect upon the amount of. Moisture in the soil either in a very dry season or in a very favorable sea-son with frequent rains. The time when it would have its maximum effect would be after a wet season and when a dry period was coming on. The moisture content at this time should fall much more gradually in the cultivated than in the uncultivated land. This is shown to a slight extent in some of the records, but not to such an extent as would seem likely to occur under the most intelligent Cultivation of the soil. The small amount of data which has been collected is not sufficient, however, to warrant a close and final judgment in this matter. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Excerpt from Soil-Moisture Measurement As has been noted, the gravimetric method is the only commonly used direct means of measuring soil moisture. Simply, it involves taking a soil sample, weighing it, oven-drying it, reweighing, and expressing the original moisture content in percent of oven-dry weight of soil. The first step, securing the sample, is the most troublesome, the degree of difficulty depending on the condition of the soil. Sampling conditions are ideal when soil is just moist enough for easy ingress and egress of the sampling instrument, and where stones, roots, and organic matter are not a problem. Such conditions are seldom encountered. With free water in the soil, moisture can never be sampled accurately: water will drip off as the sample is removed from the ground or compaction may squeeze it out. Rapid sampling is essential to prevent undue losses. Stickiness, often a problem in wet soils, can be alleviated by keeping instruments clean. Where a wet layer overlies a dry one, samples taken from the drier levels may be contaminated. After the upper soil is wetted by a summer rain, for instance, removal of a sample may permit water to run down the hole toward drier soil. The same problem is en countered when samples are taken below a perched water table. Wet instruments add to contamination and should be dried between samplings. When the soil is dry and hard, the principal problem in fine textured soils is to get the sampling instrument in and out again. In coarse-textured soils particularly, samples may slide out of the in strument as it is withdrawn from the soil. Fortunately, after the soil dries in summer, its moisture content may fluctuate so little that frequent sampling may be unnecessary. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.