温室番茄基质栽培供液决策方法研究

Research on the decision method of supplying nutrient solution of tomatoes with substrate culture in greenhouse

为研究温室番茄基质栽培过程中供给营养液的决策方法,采用水分传感器监测基质含水量作为决策控制供液量和时间的指标,设计3个试验,即在番茄各生育期内设定基质含水量上、下限值进行供液;以基质持水量为供液上限,分别以设定的基质含水量和间隔1h监测的基质含水量为下限进行非定时和定时供液。通过对比研究供液量、供液次数、可利用养分含量、基质电导率和pH对植株长势、果实品质和产量的影响,确定适宜的供液决策方法。结果表明,1在番茄各生育期设定基质含水量上、下限条件下的供液量和供液次数不能满足植株对养分的需求,植株长势和果实品质较差,产量较低;2以基质持水量为上限,基质含水量阈值为下限条件下,虽满足植株对养分需求,但由于根系环境较劣而影响植株长势;3以基质持水量和间隔1h监测的基质含水量为供液上、下限条件下,供给养分充足,植株长势正常,果实品质较优,产量增加。由此可见,以基质持水量和间隔1h监测的基质含水量为上、下限定时供液的方法,可根据番茄日需水规律实现基质栽培下营养液的高效决策管理。

To research the decision method of supplying nutrient solution of tomatoes with substrateculture in greenhouse, using the substrate water content monitored by moisture sensor asdecision index of the amount and time for supplying nutrient solution, three experiments are conducted,which set the threshold ranges of upper and lower limit of substrate water content in theeach growth periods of tomatoes to supply solution, and set the substrate water capacity as upperlimit and those as lower limits which the known thresholds of substrate water content and thesubstrate water contents by monitoring every 1 hour to supply solution with off-time and fixedtiming. Appropriate decision method of supplying nutrient solution is determined, through comparingeffects of amount and time for supplying nutrient solution, available nutrient content, electricalconductivity and pH in the substrate, plant growth, fruit quality and yield in the threeexperiments. The results show three points. The first, the amount and time for supplying nutrientsolution can not meet the requirements of plants for nutrients under the condition of the differentthreshold ranges of upper and lower limit of substrate water content in each growth periodof tomatoes, so that it gets poorer plant growth, fruit quality and lower yield. The second,though the demand of plants for nutrients is met under the condition that the substrate water ca-pacity and the known thresholds of substrate water content respectively as upper and lower limits,plant growth are affected by the bad root environments. The third, under the condition thatthe substrate water capacity and the substrate water contents by monitoring every 1 hour respectivelyas upper limit and lower limits, the demand of plants for nutrients are met, thus it gets thenormal plant growth, better fruit quality and the higher yield. The third decision method can realizethe efficient decision management of nutrient solution with substrate culture, according tothe daily water demand regulation of tomatoes.