Soil value

Abstract: Soil erosion from agricultural lands can be reduced by adoption of conservation management practices. The objectives of this study were to investigate the effectiveness and cost-benefit of conservation management practices on sediment reduction under a corn—soybean rotation. The experimental site was 6.4 ha (15.8 ac) and located within the Four Mile Creek watershed in eastern Iowa. Management practices consisted of tillage with a mold-board plow with a row cropped system of corn and soybeans. Annual sediment yield from this site was estimated using the Water Erosion Prediction Project (WEPP) model for three tillage systems (chisel plow, disk tillage, and no-tillage) as well as three conservation structures (grassed waterways, filter strips, and terraces). The WEPP model was validated using five-year (1976 to 1980) field-measured sediment yield and surface runoff data. Without supplemental conservation measures, predicted sediment yield was 22.5, 17.7, and 3.3 t ha−1 y−1 (10.0, 7.9, and 1.5 tn ac−1 yr−1) from chisel plow, disk tillage, and no-tillage, respectively. Supplemental conservation measures had the most impact on sediment yield reduction when used in conjunction with chisel plow management and the smallest impact with the no-tillage system. The value of lost soil resulting from soil erosion ranged between $10.9 and $137.3 ha−1 y−1 ($4.4 and $55.6 ac−1 yr−1) for the simulated scenarios in the study when a soil value of $6.1 t−1 ($5.5 tn−1) was considered. When factoring in the value of soil, no-tillage was the most efficient practice with the highest net benefit of $94.5 ha−1 y−1 ($38.2 ac−1 yr−1). This study indicated that the economic value of soil that is lost should be considered in the cost-benefit assessment of conservation practices in order to reflect the true value of the conservation practices in the long term.

Abstract: With the intensified pressure of population increase on natural resources and the environment in China, changes in soil quality, especially in soil fertility, have become the focus of increasing world wide concern The aim of this paper is to try to precisely judge the new changing trend in soil fertility and quality in China for the sake of providing scientific basis for decision making to policy makers Data used in this article is from the second national soil census conducted in 1982 1986 and the follow up soil survey based on the sample plots of the soil census done by Nanjing Institute of Soil Science in 2000 Five soil chemical indicators-organic matter total nitrogen, effective phosphorus, effective potassium, and pH value, with close relation to the crops growth, are selected as the primary analytical variables of soil fertility In this paper, agricultural soil fertility and quality changes from the early 1980s to 2000 were described by using data from 3 regions in China-the Northeast, the North China Plain and the middle and lower reaches of the Yangtze River-covering 180 sample plots in 15 counties of 6 provincesinThe principle for sample plot and data selection in the study is that soil fertility indicators mentioned above should be recorded both in the early 1980s and 2000 on sample plot basis Meanwhile, soil sampling season and analytical methods of soil experiments in the two periods should be basically the same so as to guarantee data from each plot of the two periods one to one correspondence and comparably in agreement This is one of the reasons accountable for the more reliable and more convincing analysis and conclusions of the present paper than other similar studies The results show that, on average, soil organic matter, total nitrogen and effective phosphorus content have been increased since rural reform in China, although soil effective potassium and pH value degraded From the perspective of spatial distribution, however, there exist significant variations in soil fertility and quality The average soil fertility rose in North China and the middle and lower Yangtze River basin, and dropped in Northeast China Additionally, with the exception of North China, which saw an improvement in soil pH value, acidification tendency was observed in the middle and lower reaches of the Yangtze River and Northeast China

Abstract: The systematic and comprehensive geochemical analysis of fluoride (F) in twenty agricultural soil samples was carried out to understand spatial variability, mechanism of retention and release, and the areas of potential risk due to high concentrations of F in soil around Sidhi District, Central India. The spatial variations in physico-chemical parameters revealed significant difference in the methods of cultivation due to geomorphological constraints, availability of surface water and ground water etc., in the study area. The north and small pocket in central Sidhi were rich in fertile soils due to availability of surface and ground water. The southern and eastern Sidhi were rainfed areas, hence, the monocropping system by traditional methods showed less impact on the soil physico-chemical parameters. The soil F varied from 366.94 to 1178 mg/kg and 2-4 times greater than the background soil value (320 mg/kg) of the world. The pollution indexes were > 1 indicating prevalence of elevated soil fluorine.

Abstract: The mineral nitrogen (Nmin) method is generally accepted as the universal soil test for determining crop fertilizer requirements and predicting the possibility of groundwater contamination by excess nitrates (NO3). However, it must be properly calibrated both for agronomic and environmental purposes. Since 1997, the program of soil monitoring for the content of Nmin has been running in Poland. In 5,000 randomly selected sites on arable land, soil samples are collected twice a year (in early spring and autumn) from soil layers 0–30, 30–60, and 60–90 cm deep. The frozen samples are sent to the one of 17 regional agrochemical laboratories and analyzed for the content of nitrogen (N)–NO3 and N‐ammonium (NH4). The results, expressed in kg of Nmin in the given soil layer and/or in the soil profile at 0–90 cm, are collected in the data bank at the Institute of Soil Science and Plant Cultivation, State Research Institute, Pulawy. These data are made available for farmers and environment protection services. On th...