水稻生长动态控制模型的研究

STUDY THE DYNAMIC CONTROL MODEL FOR RICE CULTIVATION

本文把水稻生产过程看作一个跟踪控制系统,将其分为苗期、分蘖前期、分蘖后期、孕穗期和产量形成期五个阶段。通过田间试验,研究了五个控制因素(基肥、基本苗、蘖肥、穗肥和粒肥)和两个生态干扰因素(光照和温度)对各阶段群体性状(叶色、株高、茎蘖数)的影响,建立了13个回归模型。采用动态规划方法针对不同生态条件,分别以纯收入与产量为指标函数,进行了农艺策略的优化。结果表明,水稻叶色、株高、茎蘖数可作为反映水稻群体素质的动态指标,以阶段性水稻生长回归模型为基础的动态规划模型具有跟踪控制特性,用于水稻生产的农艺策略优化效果较好。模型给出了盐粳二号(中粳)在一般生态条件下可采用的最佳农艺策略:基肥62kg/ha,基本苗188×10~4/ha,分蘖肥92kg/ha,穗肥60kg/ha,粒肥45kg/ha,可获产量8042kg/ha,纯收入3562元/ha。

The process of rice cultivation can be treated as a tracing system and divided into five stages: namely, seedling, early tillering, late tiilerin, booting and yield format ion.Five control factors( basal fertilizer, seedling density, tiller fertilizer, panicle fertilizer and grain fertilizer),two ecological factors( illumination and temperature ) and the effects of which on the. rice population, characteristics (leaf color, plant height, number of tillers) have been studied in this paper.Based on the above factors,13 regression models were established and dynamic programming has been applied to optimize the agronomic strategies for rice cultivation according to the different ecological conditions and two indicator functions (net income and yield).The results showed that, the leaf color, plant height and number of tillers could reflect the dynamic criteria of the population quality of the rice. The dynamic programming model based on the regression modes of rice growth possessed a tracing control property and had better effect on the optimization of agronomic strategies of rice production. The optimal agronomic strategies proposed by the dynamic model under normal ecological condition for rice variety'Ya-ng Geng No.2'were:Basal fertilizer 62 kg/ha; Seedlinh density 188 ×104/haTiller fertilizer 92 kg/has Panicle fertilizer 60kg/ha.Grain fertilizer 45 kg/ha.The expected yield be 8042 kg/ha with a net income 3562 yuan/ha.