| 【Objective】As a beneficial element, Silicon plays significant role on crop growth promotion and resistance strengthen, but it research less on calcareous soil of Xinjiang.The nutrient element of Si in steel slag and water-cooling slag are plentiful, which are the rejectamenta produced by metal smelting. As steel slag and water-cooling slag are rich in Si, can be processed to be agricultural silicon fertilizer, which is an efficient path to realize the cyclic utilization of waste. However, because of steel slag and water-cooling slag have a few of heavy metal ions, applied these kind of silicon fertilizers in field will exist some ecological environmental risk.The key factor and space distribution about soil Si has been found out with an experiment. The effect of steel slag and water-cooling slag Si on soil effective Si content and maize Si nutrient, yield and fertilizer use efficiency have been investigated, in order to provide a basis for reasonable application of fertilizer.【Method】Employing spatial interpolation of Arc GIS geostatistical method, soil available silicon content(Si O2) as well as soil Si geographical distribution characteristics were investigated in irrigated grey desert soils in Shihezi region(including four sub-region of Mosuowan, Xiayedi, Anjihai and Shihezi). Moreover, the influences of soil p H, soli organic matter(SOM), soil clay content(soil texture) and soil nutritional elements(soil total N and total P) on available Si spatial distribution were studied. In the present study, a two-year field experiment was carried out in 2013 and 2014. The influence of water-cooling slag and steel slag on the growth and yield of maize were comparatively studied. And the effect of silicon application on maize silicon and phosphorus uptake, and silicon fertilizer use efficiency were analyzed. Single factor pollution index and Nemerow pollution index were applied to evaluate the environmental quality of heavy metals in soil.【Result】1) It is found that soil available Si is abundant in 0-20 cm depth of topsoil, and the average available Si content is 313.3 mg·kg-1 in Shihezi region. Soil available Si spatial distribution is heterogeneity, the topographic structure of “Mountain–Oasis–Desert” had an obvious influence on soil available silicon content spatial distribution, and it was observed that soil available Si content significantly higher in southeastern than that in northwestern in Shihezi.2) Soil available silicon content decreased significantly with soil p H increasing among soil p H range of 7.6-9.1.Soil texture(soil clay content) had marked effects of on soil available Si content, and soil available Si increased with soil clay content increasing(r=0.291,P<0.01). Furthermore, there had a positive correlated relationship between soil available Si with SOM and soil total P, no statistical relation was observed between soil available Si content with soil total N.3) It was found that both silicon fertilizers of water-cooling slag and steel slag significantly increased soil available silicon content(P < 0.05). For instance, in contrast to CK, soil available silicon increased by36.9%, 15.3% and 9.7% in tasseling, dough and mature stage, respectively, with the treatment of water-cooling slag application.4) The two kinds of silicon fertilizer treatments were significantly improved the leaf area index, dry matter accumulation(P < 0.05). Also, maize yields of 17979 in water-cooling slag treatment and 17134 kg·hm-2 in steel slag treatment were gained, and those increased by 18.9% and by13.3% compare to CK.5) Maize plant Si and P uptake were significantly improved by Si fertilizer application(P < 0.05), compared with CK, maize Si uptake increased by 14.6% in water-cooling slag and by 10.4% in steel slag treatment, respectively, meanwhile, P accumulated in maize increased by 11.5% in water-cooling slag and by 8.7% in steel slag treatment respectively, in contrast to CK. A significant positive correlation was observed between maize Si uptake and P nutrition(P < 0.01) furthermore, plant phosphorus nutrition, phosphate partial productivity was obviously increased with Si fertilizer application. Fertilizer use efficiency of 38.9% in water-cooling slag and 27.8% in steel slag were reached, and water-cooling slag fertilizer shown greater effectiveness than steel slag.6) The single facter pollution index of soil As, Cd in each treatment greater than 1, shows that the soil has been contaminated with As, Cd, but there is no difference between one treatment and another, from the point of nemerow pollution index, water cooling slag>steel slag>control(2014), but overall soil belonged to the relative-clean.【Conclusion】1) It is found that soil available Si is abundant in 0-20 cm depth of topsoil, and the average available Si content is 313.3 mg·kg-1 in Shihezi region. There had a positive correlated relationship between soil available Si with SOM and soil total P and clay content, soil available silicon content decreased significantly with soil p H increasing.2) The two kinds of silicon fertilizer treatments were significantly improved the leaf area index, dry matter accumulation(P < 0.05). Maize yields increased by 18.9% and by13.3% compare to CK. Maize plant Si and P uptake were significantly improved by Si fertilizer application(P < 0.05), The fertilizer use efficiency of 38.9% in water-cooling slag and 27.8% in steel slag. After applying the silicon fertilizer, soil belonged to the relative-clean. |
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