The Effect Of Soil Moisture On The Quality And Yield Of Rice Seedlings At Different Leaf Ages

This article focuses on the current phenomenon of improper water management in the field during the two-leaf and three-leaf stages of dry-cultivated seedlings in Heilongjiang Province.With the water treatment period(two-leaf and three-leaf stages)and soil moisture type(simulated wet-cultivated seedlings: sensor-measured moisture is 90%-100%;water-cultivated seedlings:maintaining a water layer of about 1cm on the surface of the soil)as treatment factors,and drycultivated seedlings with conventional management(sensor-measured moisture is 50%-60%)as a control,the seedbeds are arranged completely randomly.The corresponding seedlings are transplanted into plastic barrels(potted)or fields.The study focuses on the impact of treatment factors on seedling quality before transplanting and on population,yield,and quality indicators after transplanting.The main results are as follows:1.With the same water treatment,the treatment during the three-leaf stage has a greater impact on seedlings than the treatment during the two-leaf stage,and treatments with more soil moisture have a greater inhibitory effect on roots.Compared with the control,when the soil moisture in the seedbed is higher during the three-leaf stage,the seedling height and leaf age increase significantly(14.8%,17.0%),while the stem base width and root number decrease significantly(15.9%,22.1%),and the root surface area,white root number and neatness decrease significantly.The water-cultivated seedling state treated during the three-leaf stage results in significantly fewer roots and shorter root length than the control.2.With the same water treatment,the treatment during the three-leaf stage has a greater impact on the physiological properties of seedlings than the treatment during the two-leaf stage.Treatments with more soil moisture have weaker quality.Compared with the control,when the soil moisture in the seedbed is higher during the three-leaf stage,the fullness and robust seedling index of seedlings decrease significantly(23.0%,37.9%).3.With the same water treatment,the effect of three-leaf period treatment on the quality of seedling population after transplantation is greater than that of two-leaf period treatment.Compared with the control group,when the soil moisture content of the seedbed in the three-leaf period is higher,there is no significant difference in the tillering rate of plants;however,the photosynthetic rate and transpiration rate during the tillering period and heading period are significantly increased(17.6%,18.3%);and the dry matter weight at heading stage also has a significant decrease(19.9%);the pot capacity is significantly reduced(26.2%),and the Honda capacity is significantly reduced(22.2%).4.Compared with the control,both the two-leaf stage treatment and the three-leaf stage treatment showed a reduction in yield: compared with the control,the yield reduction effect in the potted experiment was significant,with a yield reduction of 13.3%-18.6% during the two-leaf stage and 22.1%-24.4% during the three-leaf stage;in the field experiment,both the two-leaf stage treatment and the three-leaf stage treatment also showed a reduction in yield(8.8-22.6%),but only the difference between the water layer treatment during the three-leaf stage and the control reached a significant level.The main reason for the reduction in yield is due to a decrease in the number of ears: in the potted experiment,the number of effective ears decreased by 1.8%-21.8%,and in the field experiment it decreased by 1.6%-21.3%.5.Compared with the control,the appearance quality of rice in the two-leaf stage and threeleaf stage treatments showed an increasing trend in the potted experiment(increasing by 5.9-15.8percentage points),while in the field experiment it showed a decrease in chalkiness rate(3.1-10.9percentage points).This may be due to the influence of the experimental environment,and the chalky grain rate during the three-leaf stage was significantly lower than that during the two-leaf stage in the seedbed;both the two-leaf stage and three-leaf stage treatments showed an increase in whole polished rice rate(potted 0.59-2.40 percentage points,field 0.91-1.38 percentage points)and a decreasing trend in taste value.6.The fullness of seedlings is significantly or extremely significantly positively correlated with the rooting ability of seedlings and the storage capacity of populations after transplanting,as well as rice yield and whole polished rice rate.In summary,excessive soil moisture in the seedbed during the two-leaf and three-leaf stages of seedlings(WET-UM-1.4 moisture sensor display value above 90%)can reduce seedling enzyme activity and rooting ability,inhibit the tillering ability of rice after transplanting,and even reduce the number of effective ears and yield.