[analysis of trace elements in corncob by microwave digestion-icp-aes].the contents of trace elements of zn, mg, mn, sr, fe, pb, cu and se in the corncob collected from beijing, shan-dong, jilin, yunnan, xinjiang, gansu, shanxi, shaanxi, jiangsu, neimeng in china were determined by icp-aes using microwave digestion. the optimum condition of digesting the corncob was: put 1.5 ml of 68% nitric acid and 0.5 ml of hydrofluoric acid in the pot, then digested the sample with 3 steps under the 400 w power in the microwave oven. this digesting procedure could completely an ...200717944429
selenium fractionation and speciation in agriculture soils and accumulation in corn (zea mays l.) under field conditions in shaanxi province, china.upland and paddy soils, as well as corn samples, were collected in the selenosis area of naore village, ziyang county, shaanxi province, china. a five-step sequential extraction procedure was used for selenium (se) fractionation, including soluble se, exchangeable se and carbonate-bound se, iron and manganese oxide-bound se, organic matter-bound se, and the residual se fraction. species of soluble se in upland soils included se(-2), se(4+), and se(6+). the results showed that soluble se and exch ...201222542257
microbial functional diversity, biomass and activity as affected by soil surface mulching in a semiarid farmland.mulching is widely used to increase crop yield in semiarid regions in northwestern china, but little is known about the effect of different mulching systems on the microbial properties of the soil, which play an important role in agroecosystemic functioning and nutrient cycling. based on a 4-year spring maize (zea mays l.) field experiment at changwu agricultural and ecological experimental station, shaanxi, we evaluated the responses of soil microbial activity and crop to various management sys ...201627414400
environmental se-mo-b deficiency and its possible effects on crops and keshan-beck disease (kbd) in the chousang area, yao county, shaanxi province, china.causes of keshan-beck disease (kbd) are still being probed and monitored in china. relationships between trace elements from eco-environmental systems and kbd are poorly understood although relationships between environmental se and human health have received extensive attention. in order to investigate relationships between eco-environmental geochemistry and kbd, we selected the chousang kbd area in yao county, shaanxi province, china, as an example of a prevailing kbd area applying i-se-rich s ...200312901170
spatial and temporal variations of crop fertilization and soil fertility in the loess plateau in china from the 1970s to the 2000s.increased fertilizer input in agricultural systems during the last few decades has resulted in large yield increases, but also in environmental problems. we used data from published papers and a soil testing and fertilization project in shaanxi province during the years 2005 to 2009 to analyze chemical fertilizer inputs and yields of wheat (triticum aestivum l.) and maize (zea mays l.) on the farmers' level, and soil fertility change from the 1970s to the 2000s in the loess plateau in china. the ...201425380401
[effects of nitrogen fertilization on soil respiration and temperature sensitivity in spring maize field in semi-arid regions on loess plateau].understanding the effects of nitrogen fertilization on soil respiration rate and its temperature sensitivity (q10) is of critical importance to predict the variability of soil respiration in cropland. a field experiment was established in a rain-fed spring maize cropland (zea mays l. ) in the state key agro-ecological experimental station in the loess plateau in changwu county, shaanxi province, china. the experiment comprised of two treatments: no n-fertilizer application ( ck) and n-fertilizer ...201526314133
Displaying items 1 - 6 of 6