Development of crop management techniques for higher yield by optimun control of root zone environment

为了快速方便地对根际土壤取样进行生物量测定，采用不锈钢网织物将根际土壤分成3个隔间。在番茄栽培试验中，通过与手指根际土壤取样法的比较，可以清楚地观察到根箱的效用。排盖有很多种，每一种的材质和厚度都不一样。覆盖方式或行覆盖类型的差异会影响行覆盖下的小气候和根区热环境。为了阐明行盖下的小气候和根区热条件，本文给出了观测结果，并与数值试验结果进行了比较。仿真实验与观测结果有较好的一致性。植物的生长不仅与积温有关，还与行盖与土壤表面之间的太阳辐射有关。在加拿大阿加西斯研究站进行的关于茄子行膜栽培中塑料覆盖材料颜色的试验，结果令人感兴趣。产率依次为绿、棕、黑、透明。原因被认为是地膜。材料对地膜表面以上上部的光反射和土壤加热均有影响。效果，即绿色起到了使植物开花的促进作用。另一方面，地膜材料价格为绿棕黑透明的顺序，因此地膜材料价格与蔬菜产量之间不存在相关性。指动作为非饱和水运动的优先通道是野外模拟模型中最难考虑的问题之一。今年，我们研究了均匀的两层土壤中由于不稳定的湿润锋运动而引起的指动，这些土壤的上层比下层更细，导电性更差。少

In order to sample the rhizosphere soil quickly and easily for biomass measurement, " rhizobox which was divided into 3 compartments by stainless mesh fabrics was applied. Utility of rhizobox was observed clearly as compared with the sampling method of rhizosphere soil by finger in the experiment of tomato cultivation.There are many kind of row covers, each differing in material and prosity. these differences in covering method or row cover type can affect the microclimate under the row cover and thermal environment of root zone. To clarify the microclimate under the row cover and the thermal conditions at the root zone, We presented the observation results and compared these results with the numerical-experiments results. Fairly reasonable agreement can be obtained between simulation experiments and observation results. ' The plant growth is not only relaed to the accumulated temperature but also to the solar radiation between row cover and soil surface.It is interested that the resul … More ts of the experiment on the color of plastic mulching materials in row mulch cultivation of egglpants at Agassiz Research Station, Canada. The yields was in the order of green brown black transparent one. The reason was thought to be the mulch. materials could effect to the upper part above the mulch surface in reflecting of light from mulch as well as soiI heating. effect, that is, green color effected to make flowering of plants promote. On the other hand, price of mulch materials is in the order of green brown black transparent one, therefore, there was no correlation between price of mulch materials and vegetable yields.Fingering behaving as the preferential-pathways is one of the most difficult problems to consider the simulating model of unsaturated water movement in the field. This year, we studied the fingering caused as the result of unstable wetting front movement in homogenious, two layered soil whose upper layer is finer and less conductive than the coarser than layer beneath. Less