Lime response as related to percent Al saturation, solution Al, and organic matter content.
01 Nov 1970-Soil Science Society of America Journal (Soil Science Society of America)-Vol. 34, Iss: 6, pp 893-896
About: This article is published in Soil Science Society of America Journal.The article was published on 1970-11-01. It has received 150 citations till now. The article focuses on the topics: Saturation (chemistry) & Soil organic matter.
Citations
More filters
••
TL;DR: In this paper, an integrated overview of the probable mechanisms responsible and their implications is presented and discussed, and the practical implication of the processes discussed is that organic residues could be used as a strategic tool to reduce the rates of lime and fertilizer P required for optimum crop production on acidic, P-fixing soils.
Abstract: High rates of lime and fertilizer-P are characteristically required to obtain high crop yields on highly weathered acid soils. Much of the agriculture in the southern tropical belt, where acid soils predominate, is carried out by resource-poor, semi-subsistence farmers who are unable to purchase large quantities of lime and fertilizer. There are, however, a number of reports that additions of organic residues to acid soils can reduce Al toxicity (thus lowering the lime requirement) and improve P availability. The literature regarding these effects is sparse and disjointed and an integrated overview of the probable mechanisms responsible and their implications is presented and discussed. During decomposition of organic residues, a wide range of organic compounds are released from the residues and/or are synthesized by the decomposer microflora. The two most important groups in relation to Al toxicity and P availability are soluble humic molecules and low molecular weight aliphatic organic acids. Both these groups of substances can complex with phytotoxic monomeric Al in soil solution thus detoxifying it and they can also be adsorbed to Al and Fe oxide surfaces consequently blocking P adsorption sites. During residue decomposition, there is often a transitory increase in soil pH and this induces a decrease in exchangeable and soil solution Al through their precipitation as insoluble hydroxy-Al compounds. It also confers a greater negative charge on oxide surfaces and thus tends to decrease P adsorption. The increase in pH has been attributed to a number of causes including oxidation of organic acid anions present in decomposing residues, ammonification of residue N, specific adsorption of organic molecules produced during decomposition and reduction reactions induced by anaerobiosis. There are also mechanisms specific to either Al detoxification or improved soil P status. For example, regular applications of organic residues will induce a long-term increase in soil organic matter content. Complexation of Al by the newly-formed organic matter will tend to reduce the concentrations of exchangeable and soluble Al present. As organic residues decompose, P is released and this can become adsorbed to oxide surfaces. This will, in turn, reduce the extent of adsorption of subsequently added P thus increasing P availability. The practical implication of the processes discussed is that organic residues could be used as a strategic tool to reduce the rates of lime and fertilizer P required for optimum crop production on acidic, P-fixing soils. Further research is, therefore, warranted to investigate the use of organic residues in the management of acid soils.
540 citations
Cites background from "Lime response as related to percent..."
...Indeed, Al concentrations in soil solution have been observed to be closely related to inhibition of plant growth in acid soils (Adams and Moore, 1983; Evans and Kamprath, 1970)....
[...]
...Similarly, Evans & Kamprath (1970) observed less exchangeable Al in organic than mineral soils even when the pH of the organic soils was lower....
[...]
••
TL;DR: In this paper, the authors bring together examples of low-input soil management technology adapted to well-drained, acid, inherently infertile soils of the American tropics classified mainly as Oxisols and Ultisols.
Abstract: Publisher Summary The purpose of this chapter is to bring together examples of low-input soil management technology adapted to well-drained, acid, inherently infertile soils of the American tropics classified mainly as Oxisols and Ultisols. Soil taxonomy terminology, including soil moisture regimes, is used. The outcome of the race between world food production and population is determined in the tropics, where most of the world's undernourished people live. The applicability of high-input soil management technologies, however, diminishes in marginal lands where soil and water constraints are not easily overcome at low cost. The rising price spiral of petroleum-related products since has limited the economic feasibility of soil management technologies based on the intensive use of purchased inputs, particularly for farmers with limited resources in the tropics. The term ‘‘low’’ is used in relation to “high”-input technology where the application of fertilizers and amendments largely eliminate chemical soil constraints. The identification of plant species and ecotypes tolerant to the main acid soil stresses allows the development of low-input soil management systems for Oxisol and Ultisol regions where socioeconomic constraints prevent the widespread application of large quantities of lime and fertilizers. The basic approach is to use plants adapted to acid soil constraints, to maximize the use of fertilizers and lime needed to produce about 80% of their maximum yield, and to take advantage of favorable attributes of acid, infertile Oxisols and Ultisols.
527 citations
••
01 Jan 1992TL;DR: In most cultivated soils, the plow layer is treated periodically with fertilizers and lime to correct obvious problems of mineral element deficiency or toxicity as mentioned in this paper, and most plant rooting difficulties are imposed by the sub-plow layer of the soil profile.
Abstract: In most cultivated soils, the plow layer is treated periodically with fertilizers and lime to correct obvious problems of mineral element deficiency or toxicity. Hence, most plant rooting difficulties are imposed by the sub- plow layer of the soil profile. Such problems may be physical (plow pans or genetic hardpans) or chemical (mineral element toxicities or deficiencies) in nature or both. In any event, the problem is often manifested as drought and poor use of subsoil nutrients associated with shallow rooting.
400 citations
••
TL;DR: In this article, the fertility capability soil classification (FCC) system is introduced for the tropics and the main changes are to include the former h condition modifier (acid, but not Al-toxic) with "no major chemical limitations" and to introduce a new condition modifier m that denotes organic carbon saturation deficit.
324 citations
Cites background from "Lime response as related to percent..."
...A soil pH value of less than 5.5 usually indicates this problem (Evans and Kamprath, 1970)....
[...]
••
01 Jan 1984276 citations