Effect On Peanut Leaf Physiological Characters, Yield And Seed Quality Under Nitrogen Drip Fertilizer In Different Stages

Nitrogen fertilizer is of great significance on crop growth and crop yield, reasonable nitrogen fertilization is an important approach to adjust the crop growth and increase production. This research explored effects on peanut plant physiological characteristics, yield and quality between traditional one-time basal nitrogen fertilization and topdressing in different stages by nitrogen drip irrigation on low and high nitrogen fertility soil. Pool-culture experiments were conducted at the Field Crop Research Station of Shandong Agricultural University. Shanhua13 was chosen to be the experimental variety. Four N fertilizer treatments were applied as followed: N0(180 kg ha-1 as basal fertilizer), N1(90 kg ha-1 as basal fertilizer and 90 kg ha-1 at the pod formation stage), N2(90 kg ha-1 as basal fertilizer and 90 kg ha-1 at the pod filling stage) and N3(90 kg ha-1 at the pod formation stage and 90 kg ha-1 at the pod filling stage) on low and high nitrogen fertility soil, respectively. The main research results are as follows: 1 Effect on soil nitrogen nutrition under the condition of nitrogen drip fertilizer in different stagesBefore pod formation stage, soil nitrogen content was higher under the traditional one-time nitrogen basal fertilization than nitrogen topdressing in different stages, but after topdressing at the pod formation stage pod filling stage, soil nitrogen content was higher under nitrogen topdressing in different stages than the traditional one-time nitrogen basal fertilization. This suggested that soil nitrogen supplying capacity was enhanced under nitrogen topdressing in different stages, which was beneficial to promote the absorption of peanuts for nitrogen, the nitrogen use efficiency was improved, so that the peanut yield was increased. 2 Effect on peanut plant growth and biomass under the condition of nitrogen drip fertilizer in different stagesIt was beneficial to regulate the vegetative growth of peanut plants under nitrogen topdressing in different stages, plant growth was promoted after nitrogen topdressing at the late development stage, main stem height, side-branch length, node number of main stem and green leaves number of main stem of peanut were all promoted. Shedding of leaves was delayed under nitrogen topdressing in different stages, peanut biomass production was improved, so that aboveground biomass at the late development stage was increased. N1 treatment was advantageous to the peanut biomass accumulation before pod fiiling stage, and it could last for a longer effector phase. N3 treatment was stronger for the promotion of pods enrich. 3 Effect on peanut leaf physiological characteristics and plant senescence under the condition of nitrogen drip fertilizer in different stagesPlant premature aging is the important reason for the crop yields falling. SOD, POD and CAT activity of penut leaves at the late development stage were improved under the condition of nitrogen drip fertilizer in different stages, MDA content was declined, soluble protein content was increased, the falling of leaf SPAD value was delayed, leaf photosynthetic rate and leaf area index were also improved, so that peanut senescence was put off. Peanut senescence and decline of marked leaf function at the late development stage were delayed after top dressing at the stage of pod formation and pod filling under the condition of nitrogen drip fertilizer in different stages compared with the traditional fertilization. Photosynthetic rate and leaf area index were improved, photosynthetic time was extended, that made the peanut yield was improved. 4 Effect on peanut nitrogen accumulation, distribution and use efficiency under the condition of nitrogen drip fertilizer in different stagesOne-time basal nitrogen fertilization causes loss of nitrogen, declines the nitrogen use efficiency. Topdressing nitrogen in different stages increased nitrogen content in peanut organs at the late development stage, improved the amounts of nitrogen accumulation and enhanced the nitrogen use efficiency. At the late development stage, compared with basal nitrogen fertilization, nitrogen content in leaf and stem was improved by 8.33%-24.75% and 4.48%-19.46% under topdressing nitrogen fertilizer in different stages, nitrogen accumulation of aboveground was improved by 6.0%-39.98%, nitrogen use efficiency was improved by 0.7-1.15 times, at the same time, agronomic efficiency from nitrogen fertilizer and partial factor productivity from nitrogen fertilizer were also improved. 5 Effect on peanut yield and seed quality under the condition of nitrogen drip fertilizer in different stagesPeanut pod yield was improved under topdressing nitrogen fertilizer in different stages, compared with N0, pod yield of N1, N2 and N3 on low nitrogen fertility soil was improved by 20.63%, 8.45% and 11.31%, respectively, on high nitrogen fertility soil it was improved by 8.12%, 8.99% and 15.29%, respectively. Peanut percentage of sound pods, percentage of sound kernels and kernel rate was improved by 0.5%-12.23%, 3.66%-10.66% and 1.15%-3.01%, respectively, through this peanut pod yield was improved. Nitrogen basal fertilization or topdressing at pod formation stage could improve peanut weight of 100-sound pods and weight of 100-sound kernel, Nitrogen topdressing at pod formation stage or at pod filling stage could improve peanut percentage of sound pods and percentage of sound kernels. Yield of N1 was the highest on low nitrogen fertility soil and N3 treatment gained the highest yield on high nitrogen fertility soil.Peanut seed quality was improved under topdressing nitrogen fertilizer in different stages, it was better for transferation of assimilation products to seeds and the enrichment and full of seeds. Crude protein, oil, total amino acid and linoleic acid content of seeds were also increased. 6 Different principle of nitrogen fertilization on different fertility soilsN1 treatment gained higher biomass and pod yield on low nitrogen fertility soil, while N3 treatment gained higher biomass and pod yield on high nitrogen fertility soil. Therefore, in order to ensure the growth and development of plant vegetation, it should be paid attention to fertilize nitrogen appropriately at the early stage besides topdressing at the late development stage on low nitrogen fertility soil. While it should be valued to fertilize nitrogen at the late development stage on high nitrogen fertility soil.