【作者】 李建设；

【导师】 程智慧；

【作者基本信息】 西北农林科技大学 ， 蔬菜学， 2011， 博士

【摘要】 营养液的配制和管理是无土栽培的关键技术。配制营养液的水质影响营养液的组成和某些元素的有效性,有时甚至严重影响作物生长,决定无土栽培的成败。在各地无土栽培中,由于水源水质对营养液配方的影响,而造成无土栽培作物生长不良或减产的现象时有发生。我国广大北方地区属硬水地区,地下水水质较差。本研究在分析银川平原地下水质的基础上,筛选基于区域地下水水质特点的蔬菜营养液配方,为该地区蔬菜无土栽培提供技术支撑。试验取得以下主要结果:1.对宁夏境内沿黄河的中卫市、吴忠市、青铜峡市、永宁县、银川市、贺兰县、平罗县不同深度的温棚井水取样分析表明:银川平原多数井水水质的pH、全盐、HCO₃^-、Ca²⁺、Mg²⁺、Na⁺、Cl^-、SO₄^2-离子均偏高,对蔬菜无土栽培不利,要发展无土栽培需针对水质特点筛选营养液配方。2.植物吸收Na⁺与Cl^-较少,原水中Na⁺与Cl^-Cl高会造成营养液或基质中盐分积累。银川平原地下水中Na⁺、Cl^-含量高是水质差的主要因素之一。以雨水配制的营养液中添加500 mg/L的NaCl（Na⁺约为200 mg/L）对小白菜生长虽有抑制作用,但影响不大,可以水培生产小白菜。表明银川平原大多数水质可以水培叶菜。3.在适宜的酸性条件下,营养液不加钙和镁,银川平原地下水中原有的钙和镁可以满足小白菜植株生长的需要,未见明显的缺素症状。说明在调酸条件下银川地区地下水中的Ca²⁺、Mg²⁺可充分利用,配制营养液时应根据地下水中Ca²⁺、Mg²⁺浓度决定是否需要补充Ca²⁺、Mg²⁺。4.不同pH下水培小白菜试验,营养液在pH 6.5～5.5下小白菜形态指标、吸水速度、pH、EC值、地上部和地下部的营养元素、无机养分的吸收速度均优于营养液在pH 7.5～8.5下的指标,即pH 7.5～8.5营养液不适宜于小白菜水培生长,而6.5与5.5的pH环境下营养液适合。考虑到成本因素,使用银川地区地下水配制营养液时,将pH调整到6.5即可。由于银川平原地下水中SO₄^2-较高,调酸以硝酸和磷酸配合使用为宜。5.应用四元二次通用旋转组合设计,对小白菜、空心菜营养液配方中的NO₃^-N、P、K、Ca四种元素的摩尔浓度进行综合研究。（1）分别获得小白菜、空心菜产量（Y）与营养液中四种元素的摩尔浓度（X₁,X₂,X₃,X₄）回归模型: Y_小白菜=141.42857 +10.55542X₁ +6.40792X₂ +8.05042X₃-7.95996X₁²-9.66621X₂²-4.55246X₃²-4.69121X₄²+5.91688X₁X₄Y空心菜= 89.86543+9.23667X₁+3.08000X₂ + 5.55083X₃-5.44907X₁²-8.84032X₂²-4.03407X₃²+2.46218X₄²+3.79500X₁X₃（2）四种营养元素对供试蔬菜产量的影响各不相同,线性项是:X₁>X₃>X₂>X₄,即各个元素对小白菜、空心菜的影响大小顺序是:氮>钾>磷>钙。（3）通过对模型的解析,分别得到小白菜氮与钙、空心菜氮与钾的交互效应,且它们的交互效应在较低水平时有一定的正相关关系,在较高水平时存在着一定的负相关关系。（4）通过计算机模拟寻优,小白菜要达到单株最高产量148.75 g,营养液最优配方中NO₃^-N,P,K,Ca浓度分别是9.0、0.5、4.5、3.0 mmol/L;空心菜要达到单株最高产量108.81 g,NO₃^--N,P,K,Ca浓度分别是9.0、0.5、4.5、0 mmol/L。由于银川平原地下水中已有2 mmol/L的Ca,因此配制营养液时最佳配方中NO₃^--N,P,K,Ca添加量应分别调整为小白菜9.0、0.5、4.5、5.0 mmol/L;空心菜9.0、0.5、4.5、2.0 mmol/L。（5）模型验证试验中,通过测定各处理生长势、根系活力、产量、品质以及全氮磷钾含量表明,由模型推出的最佳配方栽培的小白菜、空心菜的以上指标含量均显着高于对照,而由模型推出的较差配方栽培的小白菜、空心菜的以上指标含量均显着低于对照,从而证明了模型的准确、可靠。6.高NaCl（Na 21.7mol/l）条件下,水培小白菜时营养液中NO₃^-ーN:NH₄^-N=8:0、7:1、6:2、4:4的四个处理中,以6:2最好,显著促进生长发育,产量高,叶色加深,可食部分硝酸盐含量降低。更多还原

【Abstract】 The nutrient solution and management is the key technology in the soilless culture. The quality of the water, which is used in these preparations, may affect the composition of solution and the effectiveness of some elements more or less, sometimes it can influence the crop growth severely, and in other words the water quality can determine the success of the soilless culture. The different water quality can sometime make the soilless crop to be performed mal-growth or reduce yields. The most of northern parts of China belong to the hard water areas, where the underground water quality is poor. Based on the analyzing the water quality, this study is to screen the solution formula which is based on the regional underground water, and is to provide the technical support for the soilless vegetable culture. The following are the main results:1. After analyzing the water samples, which were taken from the well with different depth in the greenhouse fields from Zhongwei City, Wuzhong City, Qingtongxia City, Yongning Couty, Yinchuan City, Helan Couty, and Pingluo Couty, which are along the Yellow River in Ningxia, the results showed that the quality of the most water taken from well in Yinchuan Plain is not suitable for the soilless culture, because the pH, total salt, HCO₃^-,Ca²⁺,Mg²⁺,Na⁺,Cl^-,SO₄^2- are too high to be suitable for the soilless culture. In order to develop the industry of soilless culture, the formula of the solution should be studied and screened.2. The plants absorb element of Na⁺ and Cl^- in a very fewer level, but the high concentration of Na⁺ and Cl^- in the original water can make the salt accumulation in the solution or media. The high content of Na⁺ and Cl^- in the underground water in Yinchuan Plain is regarded as an indicator of poor water quality. Though there is little inhibition to Brassica rapa L. Chinensis Group in nutrient solution by rainwater which is added NaCl by 500 mg/L （the concentration of Na⁺ is about 200 mg/L）, the inhibition is minor, and B. rapa can be cultured by Hydroponics. It indicates that leaf vegetables can be planted by Hydroponics in Yinchuan Plain.3. Under the suitable acid condition, no Ca²⁺ and Mg²⁺ added nutrient solution can fulfill the needs of plants, and no significant shortage symptoms is performed. All this indicated that Ca²⁺ and Mg²⁺ in the original water can be utilized adequately under regulating acid condition, so when the nutrient solution is prepared, Ca²⁺ and Mg²⁺ may not need to be added in according to the their content in the original water.4. In the experiments of Hydroponics at different pH, the result showed that, B. rapa grows better at pH 6.5 5.5 than at pH 7.5 8.5 in the following indexes: the morphological index, water absorption rate, pH, EC, the values of nutrients in shoot and root, inorganic nutrient uptake rate. In other words, the solution pH at 7.5～8.5 is not suitable for the growth of Chinese cabbage, and the pH 6.5～5.5 is suitable. Considering the cost, the pH in the solution in Yinchuan area can be adjusted to 6.5, and Nitrate acid or phosphate acid should be used to adjust pH, because the content of SO₄^2- is high enough in the original water.5. By means of quadratic general rotational design under the conditions of Deep Follow Technique, the concentrations of NO₃^-N, P, K and Ca in the formula of solution for B. rapa L. Chinensis, Ipomoea aquatica Forskwas studied comprehensively.（1） The regression model demonstrated the relationships between yield factor （Y） and four element factors the concentrations of N, P, K, Ca（X₁, X₂, X₃, X₄）were established. The each crop model is as following: YBrassica rapa=141.42857 + 10.55542X₁ + 6.40792X₂ + 8.05042X₃ - 7.95996X₁² - 9.66621X₂² -4.55246X₃² -4.69121X₄²+5.91688X₁X₄ YIpomoea aquatica= 89.86543 + 9.23667X₁ + 3.08000X₂ + 5.55083X₃ -5.44907X₁²- 8.84032X₂² -4.03407X₃²+2.46218X₄²+3.79500X₁X₃（2） Analysis result showed that: the effects of four factors on the yield of B. rapa, I. aquatica. increased by degrees in series of nitric-nitrogen（NO₃^-N）>potassium （K） > phosphorus （P） > calcium （Ca）.（3） By doing analysis for the model, we get the interaction between B. rapa’s N and Ca, I. aquatica’s N and K were significant; There is significant positive interaction between them in lower level and significant negative interaction between them in higher level.（4） By simulation with computer, the following fact are achieved: when the single plant yield of B. chinensis is 148.75 g, the optimal combination of these factors was that the concentrations of N, P, K and Ca should be 9.0 mmol/L, 0.5 mmol/L, 4.5 mmol/L, 3.0 mmol/L; when the single plant yield of I. aquatica is 108.81g, the optimal combination of these factors was that the concentrations of N, P, K and Ca should be 9.0 mmol/L, 0.5 mmol/L, 4.5 mmol/L, 0 mmol/L, For the content of Ca in the original water has been already 2 mmol/L, the optimum solution formula should be adjusted to be following when they are prepared: B. rapa, 9.0, 0.5, 4.5, 5.0 mmol/L;I. aquatica, 9.0, 0.5, 4.5, 2.0 mmol/L.（5） In the verification experiment of the model with B. rapa, I. aquatica, the optimum formula recommended from the model is all higher than the control in the following indexes: the growth vigor, root vigor, yield, quality and the content of total N, P, K, and the worst formula recommended from the model is all lower than the control. All these prove the model is accuracy and reliability.6. At the high content of NaCl （Na 21.7 mol/l ） the ratio of 6:2 for the NO₃^ー-N : NH₄^-N is the best in the 4 treatments （8:0, 7:1, 6:2 and 4:4） in the formula for hydroponics of B. rapa, it can significantly increase the growth and yield, dark the leaf color, and decrease the content of NO3– in the edible parts.更多还原