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The Effects of Long‐Time Cultivation on Some Physical and Chemical Properties of Two Rendzina Soils
Author(s) -
Laws W. Derby,
Evans D. D.
Publication year - 1950
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1950.036159950014000c0004x
Subject(s) - citation , library science , computer science
ACRE yields of the Rendzina soils developed in the Blackland area of Texas have declined considerably as a result of 50 to 100 years of cropping to cotton and other cultivated crops. Crops appear to suffer more from drought than formerly. The soil erodes badly. Most crops exhibit one or more nutrient deficiency symptoms, and unusual difficulty is encountered in correcting mineral deficiencies with commercial fertilizers. These facts suggest that poor soil structure is a limiting factor in crop production on this soil. The term "soil structure" is more or less descriptive and is not capable of being expressed by any specific measurements or numbers. However, measurements can be made of some of the physical properties of the soil which are closely related to structure and these used as indexes of soil structure. Baver (2) recently discussed the practical value of these structural indexes and Russell (9) has discussed the most widely used methods for determining them. Some of the methods discussed were total pore space, pore size distribution, permeability, the state of aggregation, and the size distribution and stability of the soil aggregates. This study was initiated to determine the type and extent of some of the physical and chemical changes resulting from long continued cropping, in direct comparison with soil under virgin prairie. The study has been confined largely to Houston black clay, which is the predominant soil type in the Blackland area.