褐土容重、緊實(shí)度、水分動態(tài)變化及對玉米生長的影響
發(fā)布時(shí)間：2018-09-09 17:32
【摘要】：遼西褐土作為遼寧主要地帶性土壤之一,其土地和光熱資源十分豐富,廣泛種植玉米等糧食作物。但其降水變率較大,旱災(zāi)頻繁;且由于長期旋耕、有機(jī)質(zhì)含量下即缺少有機(jī)物料投入引起耕層變薄、犁地層變淺、土壤板結(jié)、容重增大等物理性質(zhì)的惡化,嚴(yán)重制約玉米生長的問題已經(jīng)受到人們廣泛的關(guān)注。然而土壤物理性質(zhì)之間的相互影響,對玉米不同生育期生長發(fā)育的影響及合理的耕層結(jié)構(gòu)仍缺乏系統(tǒng)、定量的研究。本文利用根箱模擬研究了褐土容重、緊實(shí)度和水分的動態(tài)變化,三者相互關(guān)系及對玉米生長的影響,并通過深翻、秸稈還田、施用有機(jī)肥及覆膜對三種土壤物理性質(zhì)進(jìn)行改善,以促進(jìn)玉米生長發(fā)育。該研究結(jié)果可為建立褐土合理耕層評價(jià)指標(biāo)體系和選擇合理耕層構(gòu)造技術(shù)提供理論依據(jù)。研究結(jié)論如下:(1)不同耕翻深度其容重隨生育期推近及深度增加逐漸增大。0～25 cm 土層容重主要受耕作深度影響,深翻能顯著降低旋耕土壤15～25 cm 土層容重。25～45 cm 土層容重由于拔節(jié)期根系生長及灌漿期土壤含水量23%呈降低趨勢。(2)在玉米生育期內(nèi),不同耕翻深度土壤緊實(shí)度主要受土壤含水量影響。耕作對土壤緊實(shí)度的影響在0～25 cm 土層大于含水量影響,在25～45 cm 土層小于含水量的影響。深翻能顯著降低15～25 cm 土層緊實(shí)度,在玉米拔節(jié)和抽雄期最為明顯,較旋耕緊實(shí)度最大值出現(xiàn)深度可降低7.5～12.5 cm。(3)施入有機(jī)物料及覆膜均能降低各時(shí)期各土層容重和緊實(shí)度,其中覆膜處理下的容重及緊實(shí)度變化最小最穩(wěn)定,容重變化幅度平均為0.11g·cm-3,較不覆膜處理變幅至少減小0.04 g·cm-3;緊實(shí)度變幅平均為0.064 MPa,較不覆膜處理至少降低0.05 MPa。(4)無作物生長影響時(shí),通過對褐土設(shè)定不同含水量、容重對緊實(shí)度的影響研究發(fā)現(xiàn):容重和含水量對緊實(shí)度均有影響,其關(guān)系式為P=0.03070-0.5229ρ6.9739(P為緊實(shí)度、θ為含水量、ρ為容重)當(dāng)含水量低于5%時(shí),緊實(shí)度受容重影響大于含水量;當(dāng)容重高于1.3 g.cm-3時(shí),緊實(shí)度受含水量影響大于容重;且當(dāng)容重高于1.3 g.cm-3或者含水量低于5%時(shí),土壤緊實(shí)度≥2MPa,限制作物根系生長。(5)有作物生長影響時(shí),通過對不同耕作及改良措施下土壤緊實(shí)度與含水量和容重的關(guān)系擬合出指數(shù)方程如下:翻耕 15 cm 耕層 0～15 cm P=0.04274θ(-1.049)ρ20.79 R2=0.9201下層15～45 cm P=0.019860(-1.328)ρ21.77 R2=0.6547翻耕25 cm 耕層 0～25 cm P=0.09702θ(-1.523)ρ18.73 R2=0.8652下層25～45 cm P=1.605θ(-2.593)ρ19.54 R2=0.8134其擬合優(yōu)度均在0.65以上,上述方程均能定量地?cái)M合出褐土地區(qū)不同耕作深度及措施下緊實(shí)度與土壤含水量和容重的關(guān)系。與無作物生長影響的方程對比,水分動態(tài)變化過程是導(dǎo)致二者差異的主要因素。(6)深翻其根總長和根總表面積在0～15 cm 土層與旋耕處理無差異,在15～25 cm土層顯著高于旋耕處理;玉米株高莖粗及葉綠素含量則均表現(xiàn)為深翻處理更高,說明深翻有利于玉米根系在15～25 cm 土層生長及玉米地上部的生長。三種改良措施均能促進(jìn)根系及地上部生長,主要表現(xiàn)為覆膜有機(jī)肥配施秸稈秸稈。(7)緊實(shí)度主要影響15～25 cm根系生長。在抽雄期緊實(shí)度增大至2 MPa,玉米根總長增加顯著緩慢及根總表面積增長加快,根徑變粗。當(dāng)緊實(shí)度達(dá)到2 MPa時(shí),土壤容重達(dá)到1.4 g·cm-3,此時(shí)玉米根系生長受到嚴(yán)重限制;且緊實(shí)度增加對玉米生長速率影響顯著,主要表現(xiàn)為玉米株高莖粗長勢減緩,葉綠素含量增加緩慢。(8)深翻其玉米產(chǎn)量顯著高于旋耕,說明耕層深厚能促進(jìn)玉米增產(chǎn)。各改良措施(秸稈、有機(jī)肥及覆膜)均對產(chǎn)量有顯著貢獻(xiàn),除單施秸稈外其余措施對產(chǎn)量均達(dá)到極顯著貢獻(xiàn),但交互作用不顯著。(9)通過通徑分析證實(shí)土壤物理性質(zhì)對產(chǎn)量的影響主要表現(xiàn)為緊實(shí)度含水量容重/總孔隙度。在玉米生育期除播種期應(yīng)注意翻耕后水分易流失的問題;其他時(shí)期均表現(xiàn)為緊實(shí)度對產(chǎn)量有顯著影響,因此應(yīng)重視土壤緊實(shí)度的變化,尤其是干旱季節(jié)應(yīng)加重防范作物既受水分脅迫又受緊實(shí)脅迫。綜上可知,遼西褐土區(qū)由于氣候少雨,耕作方式單一等問題均導(dǎo)致耕層淺、容重及緊實(shí)度增大,通過對耕作及改良措施對容重、緊實(shí)度、水分的動態(tài)變化及其相互關(guān)系研究,找出三者關(guān)系的數(shù)學(xué)模型,探究通過措施對緊實(shí)度改良對玉米地上地下部生長發(fā)育影響,為建立褐土合理耕層評價(jià)指標(biāo)體系和選擇合理耕層構(gòu)造技術(shù)提供理論依據(jù)。
[Abstract]:As one of the main zonal soils in Liaoning Province, the cinnamon soil in Western Liaoning Province is rich in land, light and heat resources, and widely planted corn and other food crops. The deterioration of soil properties seriously restricts the growth of maize has attracted extensive attention. However, the interaction between soil physical properties and the effects of soil physical properties on the growth and development of Maize at different growth stages and the rational tillage structure are still lack of systematic and quantitative research. Dynamic changes, the relationship among the three factors and their effects on maize growth were studied. The physical properties of the three soils were improved by plowing, straw returning, organic fertilizer and plastic film mulching to promote maize growth and development. The conclusions are as follows: (1) The bulk density of different tillage depths increases gradually with the growth period and depth. The bulk density of 0-25 cm soil layer is mainly affected by the tillage depth. Deep tillage can significantly reduce the bulk density of 15-25 cm soil layer. The bulk density of 25-45 cm soil layer decreases due to the root growth at jointing stage and 23% soil water content at filling stage. Soil compactness at different tillage depths was mainly affected by soil water content during maize growth period. The effect of Tillage on soil compactness was greater in 0-25 cm soil layer than that of water content, and smaller in 25-45 cm soil layer than that of water content. Deep tillage significantly reduced soil compactness at 15-25 cm soil layer, especially at jointing and heading stages of maize. The maximum depth of tillage compactness could be reduced by 7.5-12.5 cm. (3) The application of organic materials and film mulching could reduce the soil bulk density and compactness at all stages. The change of bulk density and compactness under film mulching treatment was the smallest and the most stable, and the average change of bulk density was 0.11 g.cm-3, which was at least 0.04 g.cm-3 less than that of non-film mulching treatment. The average amplitude is 0.064 MPa, which decreases at least 0.05 MPa. (4) When there is no effect of crop growth on the compactness of cinnamon soil, the influence of bulk density on compactness is studied by setting different water content in cinnamon soil. It is found that both bulk density and moisture content have influence on compactness, and the relationship is P = 0.03070-0.5229 P 6.9739 (P is compactness, theta is water content, P is bulk density). Compactness is more affected by bulk density than water content when bulk density is less than 5%; when bulk density is higher than 1.3 g.cm-3, compactness is more affected by water content than bulk density; and when bulk density is higher than 1.3 g.cm-3 or water content is lower than 5%, soil compactness is more than 2 MPa, which limits the growth of crop roots. (5) When crop growth is affected by different tillage and improvement measures, soil compactness is greater than 2 MPa. The relationship between soil compactness and soil water content and bulk density fitted the exponential equation as follows: 0-15 cm tillage layer 0-15 cm P = 0.04274 thetheta (-1.04274)(-1.049) P 20.79 R2 = 0.9201 lower layer 15-45 cm P = 0.019860 (-1.328) P = 0.019860 (-1.328) P 21.77 R2 = 0.77 R2 = 0.77 R2 = 0.6547 tillag25 cm tillag25 cm 0-25 cm P = 0.09702 thethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethe0 The goodness of fit of 8134 was above 0.65, and the above equations could quantitatively fit the relationship between soil compactness and soil water content and bulk density under different tillage depths and measures in brown soil area. There was no difference between 0-15 cm soil layer and rotary tillage treatment, but in 15-25 cm soil layer it was significantly higher than rotary tillage treatment. The height, stem diameter and chlorophyll content of maize were higher under deep tillage treatment, which indicated that deep tillage was beneficial to the growth of maize roots in 15-25 cm soil layer and the growth of maize shoots. (7) Compactness mainly affected the root growth of 15-25 cm. At the heading stage, the total root length increased slowly, the total root surface area increased rapidly, and the root diameter became thicker. When the compactness reached 2 MPa, the soil bulk density reached 1.4 G. (8) Deep plowing significantly increased the yield of maize, indicating that deep plowing could promote the yield of maize. All the improvement measures (straw, organic fertilizer and film mulching) contributed significantly to the yield of maize. The other measures except straw application contributed significantly to the yield, but the interaction was not significant. (9) Path analysis showed that the main effect of soil physical properties on yield was compactness, water content, bulk density and total porosity. Compactness has a significant effect on yield, so we should pay more attention to the change of soil compactness, especially in dry season to prevent crops from both water stress and compaction stress. The dynamic changes of soil bulk density, compactness and water content and their relationship were studied. The mathematical models of the three relationships were found. The effects of compactness improvement on the growth and development of maize aboveground and underground parts were explored. The theoretical basis was provided for the establishment of the evaluation index system of rational tillage layer in cinnamon soil and the selection of reasonable tillage layer structure technology.
【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】：S513
，
本文編號：2233085
[Abstract]:As one of the main zonal soils in Liaoning Province, the cinnamon soil in Western Liaoning Province is rich in land, light and heat resources, and widely planted corn and other food crops. The deterioration of soil properties seriously restricts the growth of maize has attracted extensive attention. However, the interaction between soil physical properties and the effects of soil physical properties on the growth and development of Maize at different growth stages and the rational tillage structure are still lack of systematic and quantitative research. Dynamic changes, the relationship among the three factors and their effects on maize growth were studied. The physical properties of the three soils were improved by plowing, straw returning, organic fertilizer and plastic film mulching to promote maize growth and development. The conclusions are as follows: (1) The bulk density of different tillage depths increases gradually with the growth period and depth. The bulk density of 0-25 cm soil layer is mainly affected by the tillage depth. Deep tillage can significantly reduce the bulk density of 15-25 cm soil layer. The bulk density of 25-45 cm soil layer decreases due to the root growth at jointing stage and 23% soil water content at filling stage. Soil compactness at different tillage depths was mainly affected by soil water content during maize growth period. The effect of Tillage on soil compactness was greater in 0-25 cm soil layer than that of water content, and smaller in 25-45 cm soil layer than that of water content. Deep tillage significantly reduced soil compactness at 15-25 cm soil layer, especially at jointing and heading stages of maize. The maximum depth of tillage compactness could be reduced by 7.5-12.5 cm. (3) The application of organic materials and film mulching could reduce the soil bulk density and compactness at all stages. The change of bulk density and compactness under film mulching treatment was the smallest and the most stable, and the average change of bulk density was 0.11 g.cm-3, which was at least 0.04 g.cm-3 less than that of non-film mulching treatment. The average amplitude is 0.064 MPa, which decreases at least 0.05 MPa. (4) When there is no effect of crop growth on the compactness of cinnamon soil, the influence of bulk density on compactness is studied by setting different water content in cinnamon soil. It is found that both bulk density and moisture content have influence on compactness, and the relationship is P = 0.03070-0.5229 P 6.9739 (P is compactness, theta is water content, P is bulk density). Compactness is more affected by bulk density than water content when bulk density is less than 5%; when bulk density is higher than 1.3 g.cm-3, compactness is more affected by water content than bulk density; and when bulk density is higher than 1.3 g.cm-3 or water content is lower than 5%, soil compactness is more than 2 MPa, which limits the growth of crop roots. (5) When crop growth is affected by different tillage and improvement measures, soil compactness is greater than 2 MPa. The relationship between soil compactness and soil water content and bulk density fitted the exponential equation as follows: 0-15 cm tillage layer 0-15 cm P = 0.04274 thetheta (-1.04274)(-1.049) P 20.79 R2 = 0.9201 lower layer 15-45 cm P = 0.019860 (-1.328) P = 0.019860 (-1.328) P 21.77 R2 = 0.77 R2 = 0.77 R2 = 0.6547 tillag25 cm tillag25 cm 0-25 cm P = 0.09702 thethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethethe0 The goodness of fit of 8134 was above 0.65, and the above equations could quantitatively fit the relationship between soil compactness and soil water content and bulk density under different tillage depths and measures in brown soil area. There was no difference between 0-15 cm soil layer and rotary tillage treatment, but in 15-25 cm soil layer it was significantly higher than rotary tillage treatment. The height, stem diameter and chlorophyll content of maize were higher under deep tillage treatment, which indicated that deep tillage was beneficial to the growth of maize roots in 15-25 cm soil layer and the growth of maize shoots. (7) Compactness mainly affected the root growth of 15-25 cm. At the heading stage, the total root length increased slowly, the total root surface area increased rapidly, and the root diameter became thicker. When the compactness reached 2 MPa, the soil bulk density reached 1.4 G. (8) Deep plowing significantly increased the yield of maize, indicating that deep plowing could promote the yield of maize. All the improvement measures (straw, organic fertilizer and film mulching) contributed significantly to the yield of maize. The other measures except straw application contributed significantly to the yield, but the interaction was not significant. (9) Path analysis showed that the main effect of soil physical properties on yield was compactness, water content, bulk density and total porosity. Compactness has a significant effect on yield, so we should pay more attention to the change of soil compactness, especially in dry season to prevent crops from both water stress and compaction stress. The dynamic changes of soil bulk density, compactness and water content and their relationship were studied. The mathematical models of the three relationships were found. The effects of compactness improvement on the growth and development of maize aboveground and underground parts were explored. The theoretical basis was provided for the establishment of the evaluation index system of rational tillage layer in cinnamon soil and the selection of reasonable tillage layer structure technology.
【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】：S513
，
本文編號：2233085
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