Effects of Film-mulched and Dry-farming on Lodging Resistance of Medium Hybrid Rice

Effects of film-mulched and dry-farming on lodging resistance of medium hybrid rice 88S/1128 at late growth stage was studied in this study. The result suggested that the increasing of lodging resistance of rice showed a trend of no film-mulched and water-farmingfilm-mulched and water-farmingno film-mulched and dry-farmingfilm-mulched and dry-faming. The lodging index of water-farming treatment decreased by 9.47%-24.10% compared to that of dry-farming treatment,while the lodging index of no film-mulched decreased by 14.68%-17.09% compared to that of film-mulched treatment; lodging index was significant or extremely significant negative related to resistant press per plant,transpiration rate,intercellular CO2 concentration and photosynthetic rate but extremely significant positive related to biomass per plant; the largest contributed factor in lodging was the plant biomass,while the factors had greatest contribution to lodging resistance showed an order of resistant press per planttranspiration rateintercellular CO2 concentrationphotosynthetic ratestomatal conductance.

Measuring and modeling two-dimensional irrigation infiltration under film-mulched furrows

Furrow irrigation with film-mulched agricultural beds is being promoted in the arid region of northwest China because it improves water utilization. Two-dimensional infiltration patterns under film-mulched furrows can provide guidelines and criteria for irrigation design and operation. Our objective was to investigate soil water dynamics during ponding irrigation infiltration of mulched furrows in a cross-sectional ridge-furrow configuration, using laboratory experiments and mathematical simulations. Six experimental treatments, with two soil types （silt loam and sandy loam）, were investigated to monitor the wetting patterns and soil water distribution in a cuboid soil chamber. Irrigation of mulched furrows clearly increased water lateral infiltration on ridge shoulders and ridges, due to enhancement of capillary driving force. Increases to both initial soil water content （SWC） and irrigation water level resulted in increased wetted soil volume. Empirical regression equations accurately estimated the wetted lateral distance （Rl） and downward distance （Rd） with elapsed time in a variably wetted soil medium. Optimization of model parameters followed by the Inverse approach resulted in satisfactory agreement between observed and predicted cumulative infiltration and SWC. On the basis of model calibration, HYDRUS-2D model can accurately simulate two-dimensional soil water dynamics under irrigation of mulched furrows. There were significant differences in wetting patterns between unmulched and mulched furrow irrigation using HYDRUS-2D simulation. The Rd under the mulched furrows was 32.14% less than the unmulched furrows. Therefore, film-mulched furrows are recommended in a furrow irrigation system.