Study On High Yield Cultivation Model Of Dry Direct-seeded Rice In Liaoning Province

The shortage of labor and the cumbersome rice transplanting process have severely restricted the development of rice production in China.In the case of a certain area of cultivated land,in order to ensure rice production and ensure food security,we must actively improve the utilization efficiency of existing cultivated land while striving to increase the rice yield potential.Under this background,the dry direct-seeded with water-saving and labor-saving characteristics and meeting the needs of light and simplified cultivation has gradually received attention.However,there are relatively few studies in Liaoning,so this experiment is devoted to exploring a high-yield cultivation model suitable for dry direct-seeded in Liaoning.In 2016-2018,the direct-seeded rice field and potted live broadcast experiments were carried out at the Kalima Rice Experiment Station of Shenyang Agricultural University and the experimental farm of Shenyang Agricultural University,respectively.The conventional varieties of the three northeastern provinces(Longdao 11,Longdao 16,Jijing 302,Jijing 809,Jijing 113,Shennong 9903,Qianchonglang 2,Beijing 1 and Tiejing 7).On the basis of field experiment,different sowing date,sowing amount,nitrogen application level and ratio of base fertilizer and panicle fertilizer application were set up.The growth patterns,yield and composition factors of direct-seeded rice under different treatments were explored and analyzed.In order to form a high-yield cultivation technology model suitable for direct-seeded rice in Liaoning.On the basis of pot experiment,the growth process of various varieties under different sowing dates,namely the growth trend of vegetative growth period and reproductive growth period,was studied in order to provide reference for the cultivation and management of dry direct-seeded rice.The main results are as follows: 1.Using Jijing 302 and Shennong 9903 as test materials,set three sowing dates(April 19,April 24 and April 29)and 4 sowings(105kg·hm-2,150kg·hm-2,195 kg·hm-2 and 240 kg·hm-2).The results showed that under the conditions of field,the growth period and plant height of dry direct-seeded rice were significantly lower than that of the same year,but there was no significant change in the plant height of direct-seeded rice live broadcast under different sowing dates;With the delay of sowing date,the yield decreased significantly,mainly in the number of effective panicles,seed setting rate and 1000-grain weight.Under the same sowing date,there was no significant difference in yield and yield components between the yields of Jijing 302.The yield and yield components of Shennong 9903 were slightly different.The minimum amount of 105kg·hm-2 was significantly lower than that of other sowing.The main result was that the number of effective spikes was significantly reduced,indicating that the number of effective spikes was guaranteed.On the basis of the early broadcast,it is better to produce high yields on April 19 th.2.Eight varieties including Longdao 11,Jijing 302,Jijing 809,Jijing 113,Shennong 9903,Qianchonglang 2,Beijing 1 and Tiejing 7 were used as test materials,set 3 sowing dates(April 19,April 24,and April 29)and 3 sowings(300 capsules · m-2,450 capsules · m-2,600 capsules · m-2).The results showed that under the condition of direct-seeded rice in the field,the emergence rate of early sowing was lower than that of late sowing in the certain sowing period;with the delay of planting date,the germination and emergence rate increased,and the time from seeding to emergence was shortened,and the yield was shortened.Significantly lower than the early planting yield,indicating that the earlier the sowing date,the more favorable the dry direct-seeded rice to obtain more warm and light resources in the later growth stage.3.Using Jijing 302 as test material,set two nitrogen fertilizer application rates(225kg·hm-2 and 270 kg·hm-2)and the ratio of three base fertilizers to ear grain fertilizer(7:3,6:4,5:5).The results showed that under field conditions,the nitrogen application rate of rice was 225kg·hm-2,and the ratio of optimum base fertilizer to ear grain fertilizer was 7:3.Comprehensive comparative analysis found that sufficient nitrogen supply in the early stage of fertility and reasonable ratio of base to ear and grain were obtained,thus obtaining more effective panicles.4.9 varieties including Longdao 11,Longdao 16,Jijing 302,Jijing 809,Jijing 113,Shennong 9903,Qianchonglang 2,Beijing 1 and Tiejing 7 were used as test materials.Set 12 sowing dates(from April 17 th,2 days for a sowing period).The results showed that under the condition of direct-seeded rice,with the delay of live broadcast time,the growth period of most varieties was shortened accordingly,and the corresponding growth period was followed,which mainly showed the shortening of vegetative growth period,and the change of reproductive growth period was not obvious;The growth period of the Tiejing 7 is prolonged,probably due to its longer growth period,and the vegetative growth period takes a long time.