草炭保水保肥特性与葡萄根区不同施用模式效应的研究
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摘要
世界人口与粮食、资源与环境的矛盾日趋尖锐,提高水肥利用效率已成为我国农业可持续发展中亟待解决的重要科研课题,对果树根区环境和果园土壤的改良历来就是园艺工作者的研究重点。研究表明,根土系统中只对部分根区进行适当灌水施肥即可满足植物生长所需,“营养中心理论”、“局部性”、“就近供应”等是系统发育中形成的规律,充分利用这些规律使果树根区肥水集中供应,这对解决我国大部分果园“旱”、“薄”矛盾和当前果业可持续发展具有重要意义。草炭不仅能够软化土壤,提高土壤通透性,而且作为一种天然养分载体,还具有优良的保水保肥特性。中国草炭资源丰富,价格低廉,国外关于草炭研究已有很多报道,但关于中国草炭水物理特性的研究尚属空白;对其保肥特性的研究也只限于定性的论述;在草炭改土的研究中,大多是将草炭和土壤混合,但这种使用方法用量大,成本高。部分研究表明,集中利用草炭可大大提高草炭的利用效率,但关于这方面研究缺乏系统报道。因此,研究草炭保水持水、保肥供肥特性及节约化施用方式,对其在园艺和环保上的广泛应用具有重要意义。
本试验从土壤物理化学角度,系统深入地研究草炭与砂土、壤土的保水、保肥供肥特征。同时,将草炭集中利用对葡萄根系生存环境进行局部改良,调节与利用果树营养的“营养中心理论”、“局部性”等,系统全面研究了草炭不同施加模式(局部改良和混合改良)的保水保肥特性及对葡萄生长的影响等,取得如下一些主要结论:
1. 系统比较研究了草炭、砂土和壤土3 种不同质地土壤的水分特征曲线,得到了3 种质地土壤的拟合关系式。在此基础上选用草炭对砂土进行改良,进一步探讨了草炭、砂土、草炭-砂土混合基质水物理特性。
在同等压力条件下,草炭的含水量显著高于砂土、壤土。用van Genuchte 模型和Zhang—van Genuchten 模型都可较好描述3 种土壤的水分特征曲线,Brooks-Corey 模型可以很好的描述沙质和壤质土壤,但描述草炭的水分特征曲线较差。用腐质化程度低的高位草炭改良砂土,孔隙度、田间持水量、饱和含水量显著增加,基质保水能力提高;干旱处理过程中体积收缩程度也随基质中草炭含量的增加而增大。灌溉频率对基质蒸发量和水势也有显著影响,随着灌溉频率的增加,基质中草炭含量越高,表面蒸发越快。用较低的灌溉频率,纯草炭仍能保持更多的水分,为植物提供更多的有效水。
2. 以草炭、壤土、砂土、壤土-草炭、砂土-草炭的钙饱和土为样品,研究了恒温条件下氮磷钾的吸附特征,筛选出了最佳模型拟合吸附等温线和吸附、解吸动力学曲线。
草炭对氮、磷的保肥能力显著,对钾的保肥能力不显著;Freundlich 与Temkin 模
The conflicts between population and food and between resource and environment in the World are becoming sharper. How to improve water and fertilizer using efficiency was an important research task of the agricultural sustainable development in China. It was a key research for horticulturists to study on root-zone environment of fruit tree and soil improvement of orchard. Investigations showed that properly irrigating and fertilizing in partial root-zone could offer plant growth. “Theory of nutrition center”, “Local supply”and “Handy supply”were rules which come into being at plant growth process. In order to solve the problems of drought and poverty, saving water and fertilizer was significant for the sustainable development of fruit tree produce. Peat had many properties, including deducing bulk density, increasing porosity and holding water and fertilizer. Peat resource in China was very abundance, and price was low. There are many reports about peat in foreign countries. But researches on hydro-physical properties of peat were infrequent in China. Researches about properties of preserving fertilizer were limited to some qualitative dissertates. In research of soil amendments using peat, a lot of them were the mixed style, which was a kind of the waste of resource. Some researches showed that using peat in a concentrated way could improve its using efficiency, but these studies were very scarce. Therefore, studies on the characters of water and nutrient retention of peat and its using styles had significance on extensive application in horticulture and environmental protection.
This experiments systemically and extensively researched the properties of water and nutrient conservation of peat,sandy soil and loamy soil. At the same time, the living environment of root system was locally amended in a centralized way. Adjusting and using “Theory of nutrition center”, “Locally supply”, properties of water and nutrient conservation of different amended styles and their effects on grape growth were generally and systemically studied. The main results were as follows.
1. Water character curve of peat, sandy soil and loamy soil were comparatively studied. Fitting equations of 3 kinds of soil were obtained. Farther, sandy soil was amended by peat, their hydro physical properties were deeply discussed.
Under the same pressure, water content of peat was higher than sandy soil’s and loamy
soil’s. van Genuchte and Zhang—van Genuchten models could preferably describe water character curve of 3 kinds of soil. Brooks-Corey could commendably describe sandy soil’s and loamy soil’s, but could inaptly describe peat’s. Utilizing low-humified sphagnum peat to amend sandy soil, the total porosity, field capacity, saturated capacity was increased, and water retention of the medium was improved. The degree of medium shrinkage was increasing with peat content in media. Irrigation frequency had effect on the evaporation and water potential of different medium. The higher the peat content was, the higher the mean daily evaporation was from the medium surface, along with the increase of irrigation frequency. Using infrequently irrigation,the pure peat retained the more available water for the plant growth. 2. The absorption characteristics of NPK were studied under constant temperature condition, by selecting peat, sandy soil, loamy soil and the mixed soil as experimental material. Meanwhile, the optimal model was selected to fit the adsorption isotherms, adsorption and desorption kinetics. Results showed that conserving ability of peat to N and P was significantly higher than others, and conservation to K was insignificant; Freundlich and Temkin model might fit NH4+ adsorption isotherm, Freundlich model might fit K and P adsorption isotherms. By selecting Ca2+-saturated and NH4+-saturated soil, NH4+ adsorption and desorption kinetics, and phosphorus desorption kinetics were studied, and optimal model to fit adsorption and desorption kinetics of different soil was obtained. 3. Under the mixed amendment condition, Logistic model was employed to fit grape growth process; the grey relation degree analysis was used to investigate the relationship of grape growth, peat content and physical properties; the relation between grape root growth and basic properties in different typical soil was analyzed by using path analysis. Meanwhile, the optimal ratio of peat amendment and the optimal physical and chemical properties of soil were obtained. Peat added in soil increased significantly total porosity and physical clay content, and improved water and nutrients conservation of soil. When Logistic model was employed to fit the process of grape growth, it’s relative coefficient was above 0.98. According to the Logistic model, the growth process of one-year grape shoot might be divided into three periods, including earlier stage of growth, rapid growth stage and later stage of growth. The results showed that the effect of physical clay content and total porosity on one-year grape shoots was significant; the effect of special gravity was insignificant. In different treatments, 15% peat added in soil might improve root growth of grape significantly. Path analysis was used to investigate the relationship between growth of root and soil basic properties which involved bulk density, total porosity, physical clay content, total phosphorus, total potassium
and organic matter, and results showed that total porosity, physical clay content, total nitrogen, total phosphor, total potassium and organic matter were primary factors which effected on different typical root growth. At last, the bridge regression was employed to build correlative mathematic equation, and the optimal ratios of peat amendment in sandy and loamy soil were respectively 8.8 and 12.1 percentage. 4. Peat was applied to root-zone in layered style. Effects of localized amendment on the grape growth were studied in detail. The results showed that localized treatments of peat accelerated the grape growth, and effects of 7.5% and 15% were best in all treatments. For example, height, diameter, node length, chlorophyll contents and photosynthesis rate of grape shoot, root activity and dry weight increased all. Effects on root dry weight in every soil layers were significant, root density and root activity in peat layer were significantly higher than one in no peat layer, and root activity was still keeping high in growth latter phase. Growth of grape was restrained under the insufficient irrigation, but making use of peat could reduce the damage of drought. Applying urea increased total weight, chlorophyll contents, photosynthesis rate, transpiration, deduced root/shoot, and improved efficiently root activity, and can retain long-playing activity in peat layers. 5 we studied characters of holding water and fertilizer of two kinds of amended style and their effects on grape growth. Results showed that the effect of localized amendment was optimal, and its biologic effects were very significant. Peat added in soils increased capacity of water and nutrients conservation of reconstituted soils, and efficiently stimulated the grape growth. Soil amendment increased total biomass, the concentration of chlorophyII, photosynthesis, transpiration, root dry weight, root activity, and ZA、IAA and GA content, and reduced ABA content. The capacity of holding water and fertilizer and biologic effects on grape growth of localized amendment were more significant than the mixed amendment. Length per vine、daily elongation rate were higher after bud break 50-60 d. Total masses of the localized amendment in sandy soil were higher 145 % and 40 % than the control and the mixed amendment respectively. Its leaf photosynthesis, transpiration, and chlorophyII concentration were higher than the mixed amendment and the control. The localized amendment improved root activity and dry weight, and promoted effectively the balanced growth of root and shoot.
本试验从土壤物理化学角度,系统深入地研究草炭与砂土、壤土的保水、保肥供肥特征。同时,将草炭集中利用对葡萄根系生存环境进行局部改良,调节与利用果树营养的“营养中心理论”、“局部性”等,系统全面研究了草炭不同施加模式(局部改良和混合改良)的保水保肥特性及对葡萄生长的影响等,取得如下一些主要结论:
1. 系统比较研究了草炭、砂土和壤土3 种不同质地土壤的水分特征曲线,得到了3 种质地土壤的拟合关系式。在此基础上选用草炭对砂土进行改良,进一步探讨了草炭、砂土、草炭-砂土混合基质水物理特性。
在同等压力条件下,草炭的含水量显著高于砂土、壤土。用van Genuchte 模型和Zhang—van Genuchten 模型都可较好描述3 种土壤的水分特征曲线,Brooks-Corey 模型可以很好的描述沙质和壤质土壤,但描述草炭的水分特征曲线较差。用腐质化程度低的高位草炭改良砂土,孔隙度、田间持水量、饱和含水量显著增加,基质保水能力提高;干旱处理过程中体积收缩程度也随基质中草炭含量的增加而增大。灌溉频率对基质蒸发量和水势也有显著影响,随着灌溉频率的增加,基质中草炭含量越高,表面蒸发越快。用较低的灌溉频率,纯草炭仍能保持更多的水分,为植物提供更多的有效水。
2. 以草炭、壤土、砂土、壤土-草炭、砂土-草炭的钙饱和土为样品,研究了恒温条件下氮磷钾的吸附特征,筛选出了最佳模型拟合吸附等温线和吸附、解吸动力学曲线。
草炭对氮、磷的保肥能力显著,对钾的保肥能力不显著;Freundlich 与Temkin 模
The conflicts between population and food and between resource and environment in the World are becoming sharper. How to improve water and fertilizer using efficiency was an important research task of the agricultural sustainable development in China. It was a key research for horticulturists to study on root-zone environment of fruit tree and soil improvement of orchard. Investigations showed that properly irrigating and fertilizing in partial root-zone could offer plant growth. “Theory of nutrition center”, “Local supply”and “Handy supply”were rules which come into being at plant growth process. In order to solve the problems of drought and poverty, saving water and fertilizer was significant for the sustainable development of fruit tree produce. Peat had many properties, including deducing bulk density, increasing porosity and holding water and fertilizer. Peat resource in China was very abundance, and price was low. There are many reports about peat in foreign countries. But researches on hydro-physical properties of peat were infrequent in China. Researches about properties of preserving fertilizer were limited to some qualitative dissertates. In research of soil amendments using peat, a lot of them were the mixed style, which was a kind of the waste of resource. Some researches showed that using peat in a concentrated way could improve its using efficiency, but these studies were very scarce. Therefore, studies on the characters of water and nutrient retention of peat and its using styles had significance on extensive application in horticulture and environmental protection.
This experiments systemically and extensively researched the properties of water and nutrient conservation of peat,sandy soil and loamy soil. At the same time, the living environment of root system was locally amended in a centralized way. Adjusting and using “Theory of nutrition center”, “Locally supply”, properties of water and nutrient conservation of different amended styles and their effects on grape growth were generally and systemically studied. The main results were as follows.
1. Water character curve of peat, sandy soil and loamy soil were comparatively studied. Fitting equations of 3 kinds of soil were obtained. Farther, sandy soil was amended by peat, their hydro physical properties were deeply discussed.
Under the same pressure, water content of peat was higher than sandy soil’s and loamy
soil’s. van Genuchte and Zhang—van Genuchten models could preferably describe water character curve of 3 kinds of soil. Brooks-Corey could commendably describe sandy soil’s and loamy soil’s, but could inaptly describe peat’s. Utilizing low-humified sphagnum peat to amend sandy soil, the total porosity, field capacity, saturated capacity was increased, and water retention of the medium was improved. The degree of medium shrinkage was increasing with peat content in media. Irrigation frequency had effect on the evaporation and water potential of different medium. The higher the peat content was, the higher the mean daily evaporation was from the medium surface, along with the increase of irrigation frequency. Using infrequently irrigation,the pure peat retained the more available water for the plant growth. 2. The absorption characteristics of NPK were studied under constant temperature condition, by selecting peat, sandy soil, loamy soil and the mixed soil as experimental material. Meanwhile, the optimal model was selected to fit the adsorption isotherms, adsorption and desorption kinetics. Results showed that conserving ability of peat to N and P was significantly higher than others, and conservation to K was insignificant; Freundlich and Temkin model might fit NH4+ adsorption isotherm, Freundlich model might fit K and P adsorption isotherms. By selecting Ca2+-saturated and NH4+-saturated soil, NH4+ adsorption and desorption kinetics, and phosphorus desorption kinetics were studied, and optimal model to fit adsorption and desorption kinetics of different soil was obtained. 3. Under the mixed amendment condition, Logistic model was employed to fit grape growth process; the grey relation degree analysis was used to investigate the relationship of grape growth, peat content and physical properties; the relation between grape root growth and basic properties in different typical soil was analyzed by using path analysis. Meanwhile, the optimal ratio of peat amendment and the optimal physical and chemical properties of soil were obtained. Peat added in soil increased significantly total porosity and physical clay content, and improved water and nutrients conservation of soil. When Logistic model was employed to fit the process of grape growth, it’s relative coefficient was above 0.98. According to the Logistic model, the growth process of one-year grape shoot might be divided into three periods, including earlier stage of growth, rapid growth stage and later stage of growth. The results showed that the effect of physical clay content and total porosity on one-year grape shoots was significant; the effect of special gravity was insignificant. In different treatments, 15% peat added in soil might improve root growth of grape significantly. Path analysis was used to investigate the relationship between growth of root and soil basic properties which involved bulk density, total porosity, physical clay content, total phosphorus, total potassium
and organic matter, and results showed that total porosity, physical clay content, total nitrogen, total phosphor, total potassium and organic matter were primary factors which effected on different typical root growth. At last, the bridge regression was employed to build correlative mathematic equation, and the optimal ratios of peat amendment in sandy and loamy soil were respectively 8.8 and 12.1 percentage. 4. Peat was applied to root-zone in layered style. Effects of localized amendment on the grape growth were studied in detail. The results showed that localized treatments of peat accelerated the grape growth, and effects of 7.5% and 15% were best in all treatments. For example, height, diameter, node length, chlorophyll contents and photosynthesis rate of grape shoot, root activity and dry weight increased all. Effects on root dry weight in every soil layers were significant, root density and root activity in peat layer were significantly higher than one in no peat layer, and root activity was still keeping high in growth latter phase. Growth of grape was restrained under the insufficient irrigation, but making use of peat could reduce the damage of drought. Applying urea increased total weight, chlorophyll contents, photosynthesis rate, transpiration, deduced root/shoot, and improved efficiently root activity, and can retain long-playing activity in peat layers. 5 we studied characters of holding water and fertilizer of two kinds of amended style and their effects on grape growth. Results showed that the effect of localized amendment was optimal, and its biologic effects were very significant. Peat added in soils increased capacity of water and nutrients conservation of reconstituted soils, and efficiently stimulated the grape growth. Soil amendment increased total biomass, the concentration of chlorophyII, photosynthesis, transpiration, root dry weight, root activity, and ZA、IAA and GA content, and reduced ABA content. The capacity of holding water and fertilizer and biologic effects on grape growth of localized amendment were more significant than the mixed amendment. Length per vine、daily elongation rate were higher after bud break 50-60 d. Total masses of the localized amendment in sandy soil were higher 145 % and 40 % than the control and the mixed amendment respectively. Its leaf photosynthesis, transpiration, and chlorophyII concentration were higher than the mixed amendment and the control. The localized amendment improved root activity and dry weight, and promoted effectively the balanced growth of root and shoot.
引文