不同基质下番茄耗水规律及生长指标数学模拟研究

Numerical Simulation of Water Consumption and Growth Index of Tomato under Different Substrates

为了研究番茄在不同基质下耗水规律及生长指标数学模拟,于2018年在河北农业大学农田水利试验室开展试验,试验中采用3种基质,分别是A(原状土经过自然风干后与沙子、蛭石按体积比例8∶1∶1进行配制),B(河北省保定市保育栽培厂的育苗营养土),C(自配基质、草炭土、珍珠岩与蛭石按3∶1∶1体积配制);两种灌水水平(W为40 mm,D为30 mm)。同时利用MATLAB中的BP神经网络对番茄的根系生长指标进行模拟训练及预测;最终在A、B、C 3种基质、两种灌水水平下,番茄平均日耗水强度分别为0.66、0.43、1.43、1.22、0.68、0.54 mm/d;试验结果表明:番茄株高,茎粗,根尖数,根长等指标受到基质和灌水量影响显著,灌水量过低容易造成生育期内水分胁迫;在高灌水量下,基质B显著影响番茄的生长指标和耗水强度,研究结果显示“B基质高灌水W”的组合模式更适合番茄生长。

In order to study the water consumption rule and growth index of tomato under different substrates,the experiment was carried out in the Farmland Water Conservancy Laboratory of Hebei Agricultural University in 2018.Three substrates were used in the experiment,including A(prepared with sand and vermiculite by volume ratio of 8∶1∶1 after natural air drying),B(seedling nutrient soil of Baoding Conservation and Cultivation Factory,Hebei Province),and C(self-matching matrix,prepared by peat soil,perlite and vermiculite at 3∶1∶1 volume).Two irrigation levels(W of 40mm,D of 30mm)were designed.At the same time,BP neural network in Matlab was used to simulate training and forecast the growth index of tomato root.Finally,under three substrates(A,B and C)and two irrigation levels,the average daily water consumption intensity of tomato was 0.66,0.43,1.43,1.22,0.68 and 0.54mm/d,respectively.The results showed that tomato plant height,stem diameter,root tip number,root length and other indicators were significantly affected by the substrate and irrigation amount;too low irrigation amount would easily cause water stress in the growth period;the combination mode of“B matrix+high irrigation W”was more suitable for tomato growth.