Research On Nitrogen And Phosphorus Application Management Of Upland Rice

Drought and water shortage have become the key restricting factors of national food security.China is a big country of rice production and consumption,with the total output of rice ranking first among all crops,which plays an extremely important special role in China’s grain production.Upland rice is regarded as a new food source in the 21st century and one of the potential crops to ensure world food security and feed human beings.Developing upland rice industry is of great significance to ensure world food security.However,there are few researches on N and P application techniques to achieve high yield and good quality of upland rice.The best N and P fertilization for upland rice production management technology,to promote water-saving drought-resistant rice production of high quality,efficient and sustainable development,this research use the typical japonica upland rice Zhonghan 3,upland rice indica type Baohan 1 and japonica upland rice Zhenghan 10 as test materials,three experiments were carried out with three N rates,five N forms and proportions,and three P rates under drought cultivation,respectively,to study the effects of different N and P application measures on the yield formation and quality of upland rice,and to propose the high quality and efficient N and P application management techniques for upland rice.The main results are as follows:（1）With the increase of N application rate,there was no significant difference in upland rice yield between NN and HN treatments,but both treatments were significantly higher than those under LN;The Fv/Fm and qP values of adventitious roots,panicles and blade leaves at each hole increased with the increase of N application rate,and the photosynthetic capacity after flowering increased.The seed setting rate of NN and HN treatments was significantly lower than that of LN treatment,but the 1000-grain weight was significantly higher than that of LN treatment.With the increase of N application rate,chalkiness grain rate and chalkiness degree of upland rice increased firstly and then decreased,amylose content of upland rice decreased,protein content increased,and NN treatment had the highest disintegration value and the lowest reduction value.（2）Under five different NH4+-N and NO3--N ratio treatments,the leaves SPAD value and leaf net photosynthetic rate of rice plants at NH4+-N and NO3--N ratio of 1:1 were the highest,the N content of rice plants was higher,the number of panicles and grains per panicle were more,the grain filling rate was higher,and the yield was higher.Increased application of NH4+-N was beneficial to the increase of root weight,root length,root volume,root surface area and advent root number,while NH4+-N and NO3--N ratio of 1:1 was beneficial to the increase of root diameter at the early growth stage of rice plants.NO3--N alone was unfavorable to root growth and had the lowest yield,and the yield of single application of NH4+-N was not ideal.When the ratio of NH4+-N and NO3--N was 1:1,the growth and yield of upland rice were improved.（3）The yield of Zhonghan 3 was significantly increased by 10.9%and 22.8%under HP and NP treatments compared with LP,respectively.With the increase of P application rate,the adventitious root number,leaf P content,panicle number and grain number per panicle of Zhonghan 3 also increased,while the seed setting rate and 1000-grain weight decreased.The P accumulation was the highest under NP treatment,and there was a significant positive correlation between P uptake after anthesis and grain yield（R=0.8321**）.The percentage and appearance quality of whole rice under LP treatment of Zhonghan 3 were better,LP and NP were beneficial to the rice becoming soft and sticky,and further increased the amount ofP application,which was unfavorable to the improvement of cooking and taste quality.（4）Under dry farming conditions,the total N amount（pure N）of 200 kg/ha and the total P amount（P2O5）of 90 kg/ha,combined with 1:1 NH4+-N and NO3--N fertilizer management technology,can improve the yield of upland rice and rice quality,can realize the high quality,high efficiency and sustainable development of upland rice.