本文選題：外源硅 + 土壤磷��； 參考：《沈陽農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：磷素是植物生長發(fā)育所必需的營養(yǎng)元素,在農(nóng)業(yè)生產(chǎn)實踐環(huán)節(jié)中,如何高效率地利用磷素一直備受關(guān)注。目前,國內(nèi)外關(guān)于施硅改變土壤磷有效性的研究工作較多,但并未考慮到硅酸鹽的堿性和伴隨陽離子對反應(yīng)體系的影響,所以并不能準(zhǔn)確判斷硅素對土壤磷素活性作用的效果。為此,本試驗在消除硅酸鉀堿性和鉀離子影響的基礎(chǔ)上,進行室內(nèi)模擬試驗和生物試驗,研究外源硅對土壤及鐵氧化物吸附磷特性的影響,探討施硅條件下土壤磷有效性的變化,結(jié)合礦物學(xué)與土壤化學(xué)的理論,揭示外源硅改變土壤磷的吸附特征及有效性的作用機制,以期為生產(chǎn)中合理地配合施用硅、磷肥料,提高磷肥利用率,減少農(nóng)業(yè)面源污染提供科學(xué)依據(jù)。得到的主要結(jié)果與結(jié)論如下:1.在相同的磷吸附平衡濃度條件下,加硅可降低土壤對磷的吸附量。三種方程(Langmuir方程、Freundlich方程和Temkin方程)對土壤吸附磷的等溫試驗數(shù)據(jù)擬合結(jié)果均達到顯著水平。在Langmuir方程中,隨著外源硅施入量的增加,吸附平衡常數(shù)(K1)、最大吸附量(Xm)和最大緩沖容量(MBC)均逐漸減少,表明外源硅的施入會使土壤對磷的吸附速率變慢、最大吸附量減少,降低土壤對磷的吸附能力。在Freundlich方程中,隨著外源硅施入量的增加,吸附容量(K2)、吸附強度(n)均變小,說明外源硅的施入會導(dǎo)致土壤對磷吸附點位的減少,使土壤對磷的吸附強度減弱。2.在相同的磷吸附平衡濃度條件下,外源硅能抑制針鐵礦和水鐵礦對磷的吸附。在描述鐵氧化物對磷的吸附特征時,三種方程(Langmuir方程、Freundlich方程和Temkin方程)都能對其進行較好的擬合,但其中以Langmuir方程擬合的結(jié)果最優(yōu)。在Langmuir方程中,隨著外源硅施入量的增加,K1值減小,MBC降低,Xm基本保持不變,表明外源硅的施入會使鐵氧化物對磷的吸附速率變慢、吸附能力減弱,但并為改變鐵氧化物的最大吸附量。硅的施入可以使鐵氧化物表面吸附的磷酸根基團發(fā)生紅移,趨于更為不穩(wěn)定狀態(tài)。外源硅對鐵氧化物吸附磷的影響是土壤吸附磷能力減弱的主要原因之一。3.施硅后,土壤中的H_2PO_4~+離子活度增強,土壤磷位勢升高,土壤的供磷強度增強。同時,硅使土壤積累態(tài)磷的釋放量增加,土壤磷飽和度升高,提高了土壤中磷的移動性與活性。盆栽試驗結(jié)果表明,磷硅配施促進了水稻植株生長,可使株高、生物量有所增加。硅、磷的施用都不同程度提高了兩種土壤中水稻植株體內(nèi)的磷含量。
[Abstract]:Phosphorus is a necessary nutrient element for plant growth and development. How to utilize phosphorus efficiently in agricultural production has been paid more and more attention. At present, there are many researches on the effect of silicon application on the availability of soil phosphorus, but the effect of silicate alkalinity and associated cations on the reaction system is not taken into account, so the effect of silicon on soil phosphorus activity can not be judged accurately. Therefore, on the basis of eliminating the effects of potassium silicate alkalinity and potassium ion, the experiments were carried out in laboratory and biological experiments to study the effects of exogenous silicon on the adsorption characteristics of phosphorus by soil and iron oxides. This paper discusses the change of soil phosphorus availability under the condition of silicon application, combined with the theory of mineralogy and soil chemistry, to reveal the adsorption characteristics of soil phosphorus and the mechanism of the effect of exogenous silicon on the soil phosphorus adsorption, in order to reasonably coordinate the application of silicon and phosphate fertilizer in production. Improving the utilization rate of phosphorus fertilizer and reducing agricultural non-point source pollution provide scientific basis. The main results and conclusions are as follows: 1. Under the condition of the same phosphorus adsorption equilibrium concentration, adding silicon can reduce the amount of phosphorus adsorption in soil. The fitting results of the three equations, Freundlich equation and Temkin equation, were significant. In the Langmuir equation, the adsorption equilibrium constant (K _ (1)), maximum adsorption capacity (X _ (m)) and maximum buffer capacity (Langmuir) decreased with the increase of applied amount of exogenous silicon, which indicated that the application of exogenous silicon could slow down the adsorption rate of phosphorus and decrease the maximum adsorption capacity. The adsorption ability of soil to phosphorus was reduced. In the Freundlich equation, with the increase of the amount of exogenous silicon applied, the adsorption capacity of K _ (2 +) and the adsorption intensity of K _ (2 +) were all decreased, which indicated that the application of exogenous silicon would lead to the decrease of the site of phosphorus adsorption and the decrease of soil's adsorption intensity of phosphorus. Under the condition of the same phosphorus adsorption equilibrium concentration, exogenous silicon can inhibit the phosphorus adsorption of goethite and water ore. In describing the adsorption characteristics of iron oxides to phosphorus, the three kinds of equations, Freundlich equation and Temkin equation, can fit them well, but the Langmuir equation is the best. In the Langmuir equation, with the increase of the amount of exogenous silicon applied, the decrease of K1 value and the decrease of Xm remained unchanged, indicating that the adsorption rate of iron oxide on phosphorus was slower and the adsorption capacity was weakened. However, the maximum adsorption capacity of iron oxides was changed. The addition of silicon can make the phosphate group adsorbed on the surface of iron oxide red shift and tend to be more unstable. The effect of exogenous silicon on the adsorption of phosphorus by iron oxides is one of the main reasons for the decrease of phosphorus adsorption ability of soil. After the application of silicon, the activity of H2PO4 ~ + in soil increased, the potential of phosphorus in soil increased, and the intensity of phosphorus supply in soil increased. At the same time, silicon increased the release of accumulated phosphorus and increased the saturation of phosphorus in the soil, which increased the mobility and activity of phosphorus in the soil. The results of pot experiment showed that the combination of phosphorus and silicon promoted the growth of rice plants and increased the plant height and biomass. The application of silicon and phosphorus increased the content of phosphorus in rice plants.
【學(xué)位授予單位】：沈陽農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：S153
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本文編號：1776052