發(fā)布時間：2018-06-15 17:00

  本文選題：玉米 + 秸稈還田�。� 參考：《沈陽農(nóng)業(yè)大學》2017年碩士論文

【摘要】：農(nóng)作物秸稈中含有大量礦質元素,比如碳、磷、鉀、氮、鈣、鎂、硫和硅等元素,同時也含有大量的纖維素、半纖維素、木質素和蛋白質等有機質,是一種可資源化利用的"固體廢棄物資源"。本試驗的秸稈數(shù)量梯度分別為0、3750、7500、11250、15000 kg·hm-2;以不施秸稈作為對照。微區(qū)設計,微區(qū)面積5m2,三次重復。播種前按照試驗方案將玉米秸稈均勻撒在小區(qū)內,用旋耕機進行深度12-15cm的常規(guī)旋耕作業(yè)。春季播種時施入玉米一次性專用復合肥600kg·hm-2(N-P2o5-K20為25-15-15),播種密度60000株·hm-2。在玉米生長時期內采集表層土壤,分析土壤物理性狀、土壤養(yǎng)分、土壤微生物、土壤酶的動態(tài)變化及其相關性,試驗結果表明:1.秸稈還田能明顯的提高土壤養(yǎng)分,其中7500 kg·hm-2處理效果最好,在玉米完熟期時,相比于對照,土壤堿解氮提高了 38.9%,速效磷提高了 8.97%,速效鉀提高了 27.31%,有機質提高了 21.3%。2.秸稈還田能明顯的降低土壤容重、增加土壤孔隙度、提高土壤田間持水量、緩解水分散失,這種效果會隨著秸稈還田量的增加而變化加大;其中11250、15000 kg·hm-2處理的土壤容重分別比對照降低了 11.4%、14.2%。對于土壤孔隙度,對照、3570、7500、J4、J5整體呈上升趨勢,3570、7500相對于對照土壤總孔隙度的增加無顯著差異,J4、J5相對于對照呈顯著差異,分別提高了 8.2%、8.8%。對于田間持水量,方差分析結果表明,3570、J5相對于0田間持水量的增加無顯著差異(P0.05),而7500、J4相對于對照田間持水量的增加呈顯著差異,分別增加了 10.2%、11.9%。對于毛管孔隙度,隨著玉米秸稈數(shù)量的增加,土壤毛管孔隙度沒有太大的變化。3.秸稈還田能明顯降低水分的流失和蒸發(fā),灌水后,15000 kg·hm-2處理的土壤含水最在灌水后120小時內一直呈現(xiàn)急速下降的趨勢,3750 kg·hm-2處理在灌水后24小時到48小時與對照均相同急速下降,48小時到120小時下降速度慢7500、11250 kg·hm-2處理則一直呈現(xiàn)緩慢的下降趨勢。由此可見,秸稈還田可以緩解土壤水分的流失,并且隨著玉米秸稈還田量的增加,其緩解效果愈好,但是當秸稈還田量超出一定的范圍時,秸稈還田會加速土壤水分的流失。4.秸稈還田能夠明顯的增加土壤微生物的數(shù)量,土壤真菌數(shù)量在拔節(jié)期隨著玉米秸稈還田量的增加表現(xiàn)為先下降,后上升,再下降的趨勢,11250 kg·hm-2處理最多,之后快速下降。土壤放線菌數(shù)量在玉米拔節(jié)期時隨著玉米秸稈還田量的增加表現(xiàn)為先上升后下降的趨勢,11250 kg·hm-2最多,在乳熟期和完熟期,土壤放線菌數(shù)量整體都表現(xiàn)為上升趨勢完熟期土壤放線菌數(shù)量呈先上升后下降的趨勢,7500kg·hm-2處理最多。土壤細菌數(shù)量在拔節(jié)期隨著玉米秸稈還田量的增加表現(xiàn)為先上升后下降的趨勢,11250 kg·hm-2處理最多,完熟期土壤細菌數(shù)量呈先上升后下降的趨勢,7500 kg·hm-2處理最多。土壤纖維素菌在拔節(jié)始期隨著玉米秸稈還田量的增加表現(xiàn)為先下降、后上升、再下降的趨勢,11250 kg·hm-2處理最多在抽雄始期和完熟期隨著玉米秸稈還田量的增加表現(xiàn)為先上升后下降的趨勢,其中11250kg·hm-2處理最多。5.秸稈還田能夠增強土壤酶的活性,并且隨著秸稈數(shù)量的增加,土壤酶的活性越高,當秸稈的數(shù)量達到一定的值后,其活性不再增強。秸稈還田會增加玉米生育前期土壤中蔗糖酶含量,但是隨著秸稈還田時間的延長,各處理間土壤蔗糖酶的含量會慢慢的降低,在同一時期內,各處理的土壤蔗糖酶含量要高于對照。秸稈還田會增加玉米生育前期土壤中脲酶含量,但是隨著秸稈還田時間的延長,各處理間土壤脲酶的含量會慢慢的降低,在同一時期內,各處理的土壤脲酶含量要高于對照。土壤纖維素酶和土壤磷酸酶在玉米生育后期隨著秸稈還田量的增加呈現(xiàn)先上升后下降的趨勢。6.適量的秸稈還田量能夠有效的增加作物的產(chǎn)量,在7500kg·hm-2時對作物增產(chǎn)的效果最好。
[Abstract]:The crop straw contains a large number of mineral elements, such as carbon, phosphorus, potassium, nitrogen, calcium, magnesium, sulfur and silicon, and also contains a large amount of cellulose, hemicellulose, lignin and protein. It is a kind of "solid waste resource", which can be used for resources. The gradient of the amount of straw in this experiment is 037507500112501500 kg. Hm-2, respectively. With no straw as control. Microarea design, micro area area 5m2, three repetitions. Before sowing, the corn straw was evenly scattered in the plot, the conventional rotary tillage operation of deep 12-15cm was carried out by rotary tiller. The one time special compound fertilizer 600kg / hm-2 (N-P2o5-K20 25-15-15) was applied to the corn in spring, and the density of sowing density was 60000. Hm-2. During the period of maize growth, the soil physical properties, soil nutrients, soil microbes, and soil enzyme dynamic changes and their correlation were analyzed in the period of maize growth. The experimental results showed that 1. straw returning could obviously improve soil nutrients, and 7500 kg. Hm-2 treatment was the best. The soil alkali hydrolysable nitrogen was improved in the mature period of corn. 38.9%, the available phosphorus increased by 8.97%, the available potassium increased by 27.31%. The organic matter increased the soil bulk density, increased the soil porosity, increased the soil moisture content and alleviated the loss of water. This effect would increase with the increase of the amount of straw returning, and the soil treated with 1125015000 kg. Hm-2. Soil bulk density was 11.4% lower than that of the control, 14.2%. for soil porosity, control, 35707500, J4, J5 overall showed a rising trend, 35707500 compared with the control soil total porosity increased no significant difference, J4, J5 relative to the control showed significant differences, respectively, increased by 8.2%, 8.8% respectively. For field water holding, variance analysis showed that 3570, J5 phase There was no significant difference in the increase of 0 field water holding capacity (P0.05), while 7500, the increase of J4 compared with the control field water holding capacity was significantly different, the increase of 10.2%, 11.9%. for capillary porosity, with the increase of the number of corn straw, soil capillary porosity did not change too much,.3. straw returning can significantly reduce the loss of water and evaporation After irrigation, the soil water cut treated by 15000 kg hm-2 was the most rapid decline in 120 hours after irrigation, and 3750 kg. Hm-2 treatment decreased rapidly from 24 to 48 hours after irrigation, and slowed down from 48 to 120 hours and slowed down slowly by 750011250 kg. Straw returning can alleviate soil water loss, and with the increase of corn straw returning, the effect of soil moisture loss is better, but when the amount of straw returning is beyond a certain range, straw returning will accelerate the loss of soil water,.4. straw returning can obviously increase the number of soil microorganism, the number of soil fungi in jointing stage with the jointing period. The increase of corn straw returning amount was first descending, then rising and then decreasing, 11250 kg hm-2 treatment was most, and then decreased rapidly. The amount of soil actinomycetes in the Maize Jointing period increased with the increase of corn straw returning, 11250 kg. Hm-2 most, in the milk ripening period and the mature period, soil line The number of bacteria on the whole showed a trend of rising and decreasing in the amount of soil actinomycetes in the uptrend, 7500kg. Hm-2 treatment was the most. The number of soil bacteria increased first and then decreased with the increase of corn straw returning. 11250 kg. Hm-2 treatment was the most, and the number of soil bacteria in the completion period increased first. The decline trend, 7500 kg. Hm-2 treatment most. The soil cellulose bacteria in the beginning of jointing stage with the increase of corn straw returning, then rise, then rise, then descend trend, 11250 kg. Hm-2 treatment at most in the beginning and finish stage with the increase of corn straw returning to the first increase then decline trend, of which 11250kg The activity of soil enzyme can be enhanced by hm-2 treatment with most.5. straw returning, and the activity of soil enzyme is higher with the increase of straw number. When the number of straw reaches a certain value, its activity no longer increases. Straw returning will increase the content of sucrase in the soil of early maize growth, but with the extension of the straw returning time, each treatment will be treated. In the same period, the content of invertase in soil was higher than that of control in the same period. Straw returning would increase the soil urease content in the early period of maize growth, but the soil urease content in each treatment will slowly decrease with the time of returning the field, and the treatment will be treated in the same period. Soil urease content was higher than that of control. Soil cellulase and soil phosphatase showed a trend of rising and then decreasing with the increase of straw returning in the late period of maize growth..6. amount of straw returning amount could effectively increase crop yield, and the effect of increasing crop yield at 7500kg hm-2 was the best.
【學位授予單位】：沈陽農(nóng)業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：S513;S141.4
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本文編號：2022762