Impact of Crop Production on the Physical Status of a Typic Albaqualf

Abstract

Extensive tillage during long periods of time affects soil productivity by altering soil properties. Quantitative measurements were made to determine the combined effects of duration of tillage and production of soybean [Glycine max. (L.)] and rice (Oryza sativa) on selected physical and chemical properties of a Crowley silt loam (fine, montmorillonitic, thermic Typic Albaqualf). Four adjacent fields were sampled which included a virgin prairie and three fields in cultivation for 1, 12, and 30 yr. Undisturbed soil cores were taken at 0.05‐m depth intervals to 0.15 m and analyzed for soil water retention at 10, 30, 50, 80, 100, 500, and 1500 kPa, bulk density and saturated hydraulic conductivity. Organic matter content, pH, and particle size were determined on disturbed samples. Compared with the cultivated soils, the prairie had higher organic matter contents. The 12‐yr and 30‐yr fields in cultivation had higher pH values and bulk densities but lower water retained at a given pressure than the prairie and 1‐yr field in cultivation. No differences were found with respect to particle‐size distribution. For a given soil property, values of CV were affected by time in production but not by depth. The CV was low in the prairie, increased in the 1‐ and 12‐yr fields and in the 30‐yr field was similar to values found in the prairie. The greatest changes in organic matter and bulk density occurred in the initial 12 yr of cultivation. The temporal variability of organic matter contents in the surface 0 to 0.05‐m interval was mathematically modeled with both constant and variable rate equations.

Effects of long-term soil and crop management on soil hydraulic properties for claypan soils

“…This might be attributed to the higher clay content for more depths at the Field site (table 1). A similar trend was found by Scott and Wood (1989) in a study in silt loam (Albaqualf) soils; they found that for surface soil under cultivation for 30 years and a virgin prairie, soil water retention at -30 and -1,500 kPa (-4.4 to -217.6 lb in -2 ) were not significantly different, whereas water retention was significantly different for other pressures (higher water pressures).…”

Impacto do cultivo de citros em propriedades químicas, densidade do solo e atividade microbiana de um Podzólico Vermelho-Amarelo

“…Conforme Hajabbasi et al (1997), essas condições provocam decréscimo da macroporosidade, contribuindo para uma elevação nos valores da densidade do solo. O aumento da densidade do solo devido ao cultivo também pode estar relacionado com a perda de matéria orgânica (Bauer & Black, 1981;Scott & Wood, 1989). A atividade microbiana foi alterada pelo cultivo do solo (Figura 7).…”

“…Com a retirada da vegetação natural e implantação das culturas comerciais, ocorrem modificações nas propriedades dos solos. A magnitude e a direção dessas modificações dependem do tipo de solo, do clima, do cultivo e do sistema de manejo utilizado (Scott & Wood, 1989). Estudos nesse sentido foram realizados por Borges & Kiehl (1997), os quais constataram que os cultivos de banana e citros elevaram os teores de cátions no solo, principalmente no horizonte superficial de um Latossolo Amarelo álico.…”

Chemical stabilization of soil organic nitrogen by phenolic lignin residues in anaerobic agroecosystems

“…Recent developments in availability of irrigation water and the appearance of soybean rust (Phakopsora pachyrhizi) in the U.S. South might promote continuous cropping of rice, at least in fields near water bodies. Increased SOM levels under continuous rice cropping might also improve soil physical properties, thereby mitigating long-term degradation under the riceÀsoybean rotation (Scott and Wood, 1989). In a 4-yr field trial, however, grain yield of a continuous rice rotation was 19% (1.5 ton/ha) less than the grain yield of rice following soybean (Anders et al, 2004).…”