Study On Soil Moisture And Temperature Law Of Gravel-mulched Field

Gravel-mulched Field can effectively reduce surface runoff, restrain soil moisture evaporation, increase rainfall infiltration, control soil temperature, and enhance the role of crop yield ultimately. With the planting age increased of gravel-mulched field, the sand layer cover became the mixed media of sand and soil, which makes the soil moisture transport and temperature more complex. Taking bare land(no vegetation and sand mulch) as a contrast group(CK), to study the Variation law of soil moisture infiltration and temperature of new gravel-mulched field(NGM), middle gravel-mulched field(MGM) and old gravel-mulched field(OGM), and draw soil moisture infiltration and soil temperature distribution influence of gravel-mulched field sand itsplanting age. The main contents are:(1) Taking the wild field experiment, to the precipitation pulses of 7.1mm and 1.9mm within three days after the occurrence,quantitatively analyses the change law of gravel-mulched field soil moisture of different planting years with the time, and experimental results show that the soil moisture content of gravel-mulched field and the time have exponent function positive correlation, and the correlation coefficient ranges from 0.9381 to 0.9873,the increase of soil moisture content is that NGM > MGM > OGM. Both of two rainfall show that the average soil moisture content is that NGM > MGM > OGM > CK.(2) Taking in the indoor simulation experiments, to study the influence of different planting years and soil bulk density(1.23g/cm3, 1.38g/cm3, 1.53g/cm3) for point source infiltration pattern. The results showed that horizontal and vertical cumulative infiltration distance and time were in significant power function relationship and comply with Kostiakov infiltration model. Vertical infiltration distance of CK is less than the horizontal infiltration distance in the early days of infiltration and vertical infiltration distance of NGM is larger than the horizontal infiltration distance; Vertical infiltration distance of MGM, OGM and CK turned over the horizontal infiltration distance with the increase of time in the late infiltration. Point source vertical cumulative infiltration with soil bulk density and planting years were in negative correlation and bulk density has no obvious effect on the infiltration depth in the early days of infiltration, infiltration depth were significantly influenced by the density effect when infiltration reaching the soil and the bulk density larger, infiltration depth smaller.(3) Studing the dynamic variation characteristics of soil temperature under gravel-sand mulched through outdoor simulations experiment and wild field experiment. The results showed that temperature fluctuation ranges were gravel surface> 0cm(soil) > 10cm(soil) when light intensity was stable. Soil temperature fluctuation ranges was positively correlated with the light intensity. The under gravel-sand mulched temperature was quadratic or cubic polynomial relationship with the soil depth. The average soil temperature of NGM was highest in 0~20 cm, MGM and OGM was similar, the average soil temperature of OGM was highest in 30~50 cm, NGM and MGM was similar.(4) The development and output value per mu of flax plants was studied by taking field trials under the three planting patterns that were ordinary, gravel-mulched and rainwater collection, the measured results show the dry weight of plants, fruits, roots and stem emerged that CRM> GSM> CK. The dry production per mu of CRM and GSM are 13.0 times and 14.9 times as weight as CK. GSM and CRM can significantly improve the yield per mu of oil flax.