Effects Of Organic Liquid Fertilizer On Agronomic Traits,photosynthetic Physiology And Yield Of Cotton

The aim of this study is to explore a fertilization method suitable for high efficiency cotton production in arid area,break the current situation of "high input and high yield" in agricultural production,and realize the target of simultaneous improvement of nutrient utilization efficiency and cotton yield.Based on the actual cotton production in arid area,this study took Luyanmian-24 as the experimental material in 2018,and adopted drip irrigation under film to investigate the changes of cotton agronomic traits,canopy structure and yield under conventional fertilization and organic liquid fertilizer modes.Xinluzao 74 as the experimental material in 2019.The experiment was completely random designed,included F0.6(60% of conventional dosage),F0.8(80% of conventional dosage),F1.0(conventional dosage),F1.2(120% of conventional dosage),F1.4(140% of conventional dosage).The main research is the effect of the different organic liquid fertilizer dosage on cotton canopy structure,photosynthetic physiological characteristic and matter accumulation and distribution.The main research results are as follows:1.The study on the effect of organic liquid fertilizer on cotton yield and its components showed that compared with conventional fertilizer application,the application of organic liquid fertilizer could improve the plant type of cotton,effectively reduce the plant height,increase the number of main stem leaves and fruit branches,and lay the foundation for high yield of cotton.The application of organic liquid fertilizer could effectively improve the leaf area index(LAI),increase the biomass accumulation and the proportion of allocation to reproductive organs of cotton,and then increase boll number per plant and boll number per unit area by 14.4% and 13.1%,respectively,compared with conventional fertilizer application,resulting in an 11.6% increase in cotton yield.Under different organic liquid fertilizer treatments,lint yield of F0.8 treatment increased by 16.8%,11.5%,8.5% and 26.7%compared with F0.6,F1.0,F1.2 and F1.4,respectively.Further analysis of yield components showed that boll number per plant in F0.8 treatment was 0.8 and 1.27 more than that in F0.6and F1.4 treatment,but there was no significant difference among F0.8,F1.0 and F1.2treatments.There was no significant difference in boll weight and lint percentage among different treatments.2.The study on the effect of organic liquid fertilizer on cotton canopy structure showed that the LAI of F1.0 treatment was higher than that of other treatments in each growth stage,and the highest LAI of F1.0 treatment was 6.57 in the late full belling stage,which was27.23%,51.32%,36.98% and 16.26% higher than that of F0.6,F0.8,F1.2 and F1.4 in the same period,respectively.The LAI of F0.8 was maintained at a relatively stable level(3.85-4.34)during the whole growth period from the full boll stage to the boll opening stage.The Mean tilt angle(MTA)under different organic liquid fertilizer treatments was as follows:F0.6 < F0.8 < F1.0 < F1.2 < F1.4.The MAT of F1.4 treatment was significantly better than that of other treatments at the boll opening stage,but there was no significant difference among F0.8,F1.0 and F1.2 treatments.The Diffuse non-interceptance(DIFN)was as follows:F0.8 > F0.6 > F1.2> F1.0> F1.4.In the late period of full boll,the DIFN of each treatment gradually increased,but the DIFN of different treatments was different,and the DIFN of F1.0treatment increased the fastest.3.The study on the effect of organic liquid fertilizer on photosynthetic physiology of cotton showed that the chlorophyll content of F1.0 treatment decreased the most during the full boll-opening period,while the chlorophyll content of other treatments decreased more slowly,which could effectively delay leaf senescence.In the whole growth period,photosynthetic characteristics between different processing cotton(Net assimilation rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),intercellular CO2 concentration(Ci))and chlorophyll fluorescence characteristics(maximal photochemical efficiency of PSII in the light(Fv/Fm),actual photochemical efficiency of PSII in the light(Y(II)),quantum yield of PSII non-regulatory energy dissipation(Y(NO))and quantum yield of PSII regulatory energy dissipation(Y(NPQ))show little difference.4.The study on the effect of organic liquid fertilizer on the dry matter accumulation of cotton showed that the dry matter accumulation per plant under F0.8 treatment was 3.13%,7.37%,11.79% and 16.77% higher than that under F1.4,F1.2,F0.6 and F1.0,respectively.The dry matter distribution ratio of reproductive organs and various growth parameters under F0.8 treatment were significantly better than those under other treatments.From the full flowering stage to the boll opening stage,the correlation analysis showed that the total dry weight of plants,total dry weight of bolls and bolls and the population growth rate were significantly positively correlated with each other.The boll number per plant was significantly positively correlated with the total dry weight of plants,total dry weight of bolls and bolls,population growth rate and boll growth rate.In conclusion,timely and appropriate use of organic liquid fertilizer for the optimization of cotton canopy structure and improve photosynthetic performance is critical,which can delay the senescence of lower canopy cotton leaves in late growth period,and improve the population growth rate and the material production ability,increase the amount of dry matter accumulation at the same time,promote sustained to the cotton boll dry matter distribution,to ensure the high boll number per unit area,high yield of seed cotton.