Physiological Mechanism And Cultivation Techniques Of High Yield And Efficiency Winter-seeded Spring Wheat In Inner Mongolia

Winter wheat planted in Hetao Plain in Inner Mongolia is suffering winter damage,spring drought or late spring cold which lead to lower reviving rate and late harvest.The objectives of this research were to improve wheat cold and drought resistance,and to enhance grain yield and economic benefits.Wheat of different vernalization types were used to study the effect of different planting date,planting depth,planting rate and water and fertilizer management on emergence,overwintering,growth and development and grain yield formation.The relationship between climate,soil,and water,on one hand,and the growth of winter-seeded spring wheat,on the other hand,and the limit of high yield formation were going to be illustrated.The physiological mechanisms of high yield and efficiency winter-seeded spring wheat have been revealed.The matching high yield and efficiency cultivation technique system has been established too.The study is not only beneficial to enrich high yield wheat physiological mechanisms,but also to increase wheat production,reduce production cost,increase economic efficiency,raise multiple crop index and protect the environment.The main results were shown as follows:1.The spring emergence rate of the wheat varieties increased with a delay in sowing date.The emergence rate of wheat overwinter as seed was close to 60%.The winter-seeded spring wheat germinated and ripened after three and seven days,respectively,earlier than the spring-seeded.The LAI,photosynthetic performance,dry matter accumulation and yield of winter-seeded wheat increased with a delay in sowing date.The wheat sown in early November performed best.The best seeding time for the winter-seeded spring wheat in the Hetao Irrigation District of Inner Mongolia was early November.2.The emergence rate of the winter-seeded wheat was lower than the spring-seeded.The winter-seeded wheat root system was developed,and it had strong adaptability to low temperature and drought.Three wheat varieties suitable for winter-seeded in the irrigation area of Inner Mongolia Plain were selected by systematic clustering,including Yongliang 4,Ningodng 11 and Henong 7106.Their common characteristics were strong stress resistance,high emergence rate,developed root system and high yield.3.Compared with the wheat without irrigation before sowing,the wheat irrigated before sowing emerged early,has a higher emergence rate and ripened 7 days in advance.The pre-sowing irrigation had significant effects on dry matter accumulation,leaf area index and photosynthetic characteristics of winter-seeded wheat.The wheat sown 3-5 cm depth germinated and ripened after 4-5 and 5-7 days,respectively,earlier than the wheat sown more than 9 cm depth.The emergence rate,dry matter accumulation,leaf area index,photosynthetic characteristics and yield of wheat sown 3-5 cm depth performed best.4.The emergence rate presented a trend of increasing first and then decreasing with the increase of fertilizer rate,and was not significantly affected by the seeding rate.The LAI,LAD and dry matter accumulation of winter-seeded wheat increased with increasing fertilizer rate and the seeding rate.The SPAD increased first and then decrease with the increasing of seeding rate.The Pn,Tr,Gs of winter-seeded wheat all performed best under the treatment with high level fertilizer rate and the seeding rate.Compared with the spring-seeded wheat,these three factors were increased by 15.5%,9.2%and 7.9%,respectively.The yield of winter-seeded wheat increased with increasing seeding rate and it increased first and then decrease with the increasing of fertilizer rate.The regression analysis showed that the spring wheat "Yongliang 4" could get the highest yield under the suitable seeding rate(480.5 kg·ha-1)and fertilizer rate(396.2 kg·ha-1).5.Compared with spring-seeded wheat,the winter-seeded wheat has a lower emergence rate,but it emerged early with strong tillering ability,high leaf photosynthesis rate and well-developed root system.After flowering,the SPAD value,Fv/Fm value and photosynthetic rate of flag leaves decreased slowly,and the high value in stable period lasted longer.Before jointing stage,there was no significant difference in dry matter accumulation between winter-seeded and spring-seeded wheat.After flowering stage,the dry matter accumulation of the winter-seeded plants even exceeds that of spring-sown wheat,and the grain yield can also reach the same level as spring wheat.Compared with the spring-seeded wheat,panicles of the winter-seeded wheat declined,but grains per spike and a 1000-grain weight increased.Based on the above research results,the high-yield and high-efficiency cultivation model for "Winter-seeded spring wheat" in Hetao Irrigation District was established.It involves four aspects:under the premise of irrigating a sufficient amount of water,the farmland was prepared carefully before sowing;the best seeding time was early November,while seeding date should be postponed appropriately in warm winter years;the spring variety "Yongliang 4"was used;the sowing depth and seeding rate was 3-5 cm and 480.5 kg ha-1,respectively.Basal fertilizer(diammonium phosphate)was applied at the amount of 396.2 kg ha-1 during field preparation.