Effects Of Nitrogen Combined With Phosphorus On Water And Fertilizer Use Efficiency And Yield Of Oil Flax In Dry Land

An experiment was conducted to study the effects of nitrogen and phosphorus on the regulation of dry matter accumulation, distribution and transportation, nitrogen accumulation and transportation, yield, water use efficiency and nitrogen and phosphorus use efficiency of oil flax?Longyaza 1? with the treatments of no fertilizer, single nitrogen fertilization, single phosphorus fertilization, N combined with P fertilizer rate, the results were concluded as follows:1. Nitrogen combined with phosphorus increased the total chlorophyll content in leaf, per plant leaf area and per plant total dry matter accumulation of oil flax in dry land. The total chlorophyll content under nitrogen combined with phosphorus was 6.49%¹3.22%, 15.04%²2.31%, 23.97%³1.81% greater than N, P and N0P0, respectively; The leaf area under nitrogen combined with phosphorus was 35.85%⁵8.97% higher than N, 4.39%²7.90% higher than P, 23.72%³9.18% higher than N0P0; The per plant total dry matter accumulation under nitrogen combined with phosphorus was 8.44%¹5.75%, 7.45%¹4.70%, 7.67%¹4.93% greater than that of N, P and N0P0, respectively.2. The soluble sugar accumulation content showed a bimodal curve in stem and leaf in oil flax under nitrogen combined with phosphorus in dry land, nitrogen combined with phosphorus increased the soluble sugar accumulation content in stem on kernel stage. When the nitrogen and phosphorus applications were 150 kg/ha and 75 kg/ha, the export percentage of the soluble sugar in stem was highest, reached 55.09%, the export percentage of the soluble sugar in stem decreased with nitrogen and phosphorus applications increasing; When the nitrogen and phosphorus applications were 150 kg/ha and 150 kg/ha, the export percentage of the soluble sugar in leaf was highest, significantly higher than other treatments.3. With the succession of the growing stages, the trend of nitrogen accumulation was “slowly-fast-slowly”. Nitrogen combined with phosphorus increased the nitrogen accumulation content in stem of oil flax, when the nitrogen and phosphorus applications were 150kg/ha and 75 kg/ha, the nitrogen accumulation contentt of oil flax was highest than others at maturation stage. The leaf nitrogen accumulation content of oil flax showed a sigenificant unimodal curve under different nitrogen combined with phosphorus, the maximum occurs at flowering stage. The nitrogen transport content of oil flax leaves increased with nitrogen and phosphorus applications increasing under nitrogen combined with phosphorus, When the nitrogen applications were between 75 kg/ha to 150 kg/ha, the nitrogen transport content of oil flax leaves decreased with nitrogen applications increasing under single N fertilization; When the phosphorus applications were between 75 kg/ha to 150 kg/ha, the nitrogen transport content of oil flax leaves increased with phosphorus applications increasing under single P fertilization.4. The soil water storage under different fertilizer methods variation trends are similar in 0²00 cm soil layer, The soil water storage with the growth period, the rise of temperature and soil evaporation increased was gradually reduce. Nitrogen combined with phosphorus play an critical role on the soil water storage in budding and pre budding.In budding stage, When the nitrogen and phosphorus applications were 150 kg/ha and 150 kg/ha, the soil water storage was highest, which increased respectively by 1.07% 9.50%.5. Nitrogen combined with phosphorus with does not significantly affect on thousand kernel weight, but the impact on number of effective capsule per plant were significantly. The highest yield of oil flax was observed under 150kg·hm^-2 nitrogen with 75 kg·hm^-2 phosphorus treatment, which was 1746.4 kg·hm^-2, increase production 33.02%; The highest WUE was recorded under150kg·hm^-2 nitrogen with 75 kg·hm^-2 phosphorus treatment, which increased respectively by6.28% 34.62%. Under our experimental conditions, the nitrogen and phosphorus application were respectively 150 kg/ha and 75kg/ha is the best optimal fertilization application.