Effect Of Whole Film Mulch On Yield, Quality And Physiological Basis In Broomcorn Millet Under Different Planting Densities

This field experiment was taken in hequ county, Shanxi Province Yang Qiao hollow village and Inner Mongolia agricultural university respectively in 2012 and 2014. Hequ’s red broomcorn millet was used as the studied material, and setting six planting densities on effects of different planting densities on moiphological indexes (plant height, stem diameter, tiller number), photosynthetic indexes (leaf area of per plant, relative content of chlorophyll, photosynthetic rate), dry matter, yield and yield component traits was studied through completely randomized block design. Experience model with density and crop yield was simulated by nonlinear regression analysis. Yixuan yellow broomcorn millet of Hohhot cultivating and Jinshu 8 were used as the studied materialising split plot experiment design, setting the main area of four planting densities and the deputy area of whole film mulching and no mulching on effects of whole film mulching under different planting densities on yield and yield component traits,plant morphology,photosynthetic indexes, protective enzyme activity and physical matter content of leaf, soil water content, dry matter accumulation and transportation, nitrogen utilization efficiency and grain quality, reveals main influence mechanism of broomcorn millet yield and quality of the different densities and different densities under whole film mulch. Research conclusions are as follows.1. Effect of planting density on growth and yield of broomcorn millet(1) Density of Hequ’s red broomcom millet is more than 75,0000 plants/hm2 with the increased of plant density,plant height increased,stem became thinner,tiller number declined and the photosynthetic indices were decreased;Ear weight,grain weight of spike and effective grain number of spike were gradually reduced, the dry matter accumulation and the yields decreased.(2) The trend of broomcorn millet grain yield with planting density increase was first increased then decreased,equation of quadratic curve model was Y =176.78471+11.51879X-1.29607X2(R2=0.7809),theoretically optimum density range from 60,0000 plants/hm2 to 75,0000 plants/hm2.2. Effect of whole film mulching on yield, quality and physiological basis in broomcorn millet under different planting densities(1) Yixuan and Jinshu 8 with increased of planting density, the yield components reduced, the yield and harvest index first increased then decreased, and the optimum planting density range from 60,0000 plants/hm2 to 90,0000 plants/hm2; The whole film mulching works for two broomcorn millet under 75,0000/hm2 in grain-filling and yield increased, so the whole film mulching of planting density of 60,0000 plants/hm2 to 75,0000 plants/hm2.(2) Stem diamctcr,tiller number and effective tiller rate of two kinds of broomcorn millet decreased with the increased of the density of cultivation, plant height increased; Under the same density, two kinds of broomcorn millet whole film mulching plant height and stem diameter were larger than no mulch ing Effective tiller rate of whole film mulching is higher than no mulching in low density, but it is decreased in high density.(3) With the density increased, leaf area index of population increased, pholosyntheiic rate of population, chlorophyll content and light transmittanee were reduced, leaf area of 90,0000 plants/hm2 maintained short time after flowering stage, decreasing rate was fast,light transmittanee of the base increased; The whole film mulching increased population leaf area index, reduced light transmittance. increased photosynthetic rate and chlorophyll content of the two broomcorn millets in 45,0000 plants/hm2;When planting density is greater than 60,0000 plants/hm2. with increased of density, photosynlhetic rate, leaf area index and chlorophyll content of tilling stage dropped faster, light transmittanee of population base increased.(4) With the density increased, POD activity and SOD activity of two kinds of broomcorn millet decreased, MDA content increased, the proline content increased, increasing density promoted leaf senescence; In 45,0000 plants/hm2, POD and SOD activity of whole film mulching was more than no mulching; When the density was greater than 60,0000 plants/hm2, POD and SOD activity of whole film mulching was less than no mulching;MDA content and proline content of whole film mulching was less than no mulching before flowering, and with density increased, the MDA content and proline content were higher after flowering,the whole film mulching promoted leaf senescence under higher density.(5) Without mulching, water content of soil of two kinds of broomcorn millet was low in 90,0000/hm2; From heading stage,water content of soil of whole film mulching was less than no mulching, and with the density increased,water content significantly reduced; In filling stage, water content of 75,0000 plants/hm2 and 90,0000 plants/hm2 decreased to about 7%, significantly less than other treatments. Lower water content of soil led to leaf proline content increased, proline content of whole film mulching was less than no mulching before flowering, and with density increased, proline content were higher after flowering.(6) Dry matter of two broomcorn millets increased with the increasing density, dry matter of plant organs and transport rate of dry matter, mobile rate decreased with increasing density; With density increased, Yixuan and Jinshu 8 of whole film mulching dry matter of stem and leaf mobile rate dropped. Yixuan stem matter transport rate increased and Jinshu 8 stem and leaf transport rate declined; With the increasing of planting density, grain filling rate declined, the whole film mulching promoted the grain-filling of Yixuan, but it was unfavorable to grain filling of Jinshu 8 under planting density of more than 60,0000 plants/hm2.(7) With increasing of density, the plant nitrogen content two kinds of broomcorn millet decreased, nitrogen uptake of population increased, nitrogen production efficiency of grain and nitrogen harvest index were higher in 60,0000 plants/hm2 and 750000 plants/hm2; Whole film mulching improved plant nitrogen rate and nitrogen uptake of population of Yixuan.but nitrogen production efficiency of grain was lower, nitrogen harvest index increased;the effect of reducing, nitrogen production efficiency of grain and nitrogen harvest index of Jinshu 8, more than 60,0000 plants/hm2,were reduced with whole film mulching.(8) With increasing of planting density, protein content of grain,crude fat content, starch content of two kinds of broomcorn millet firstly increased and then decreased;Under the same planting density, the whole film mulching improved protein content, starch content and crude fat content in the low density, they dropped in high density; With increasing of density, inhibiting hydroxyl radicals effect, DPPH removal ability and resistance oxygen anion free radical vitality of Yixuan’s grain were increased; Whole film mulching reduced Yixuan’s suppression ability of hydroxyl radicals and antioxidant anion radical vitality in 90,0000 plants/hm2 and DPPH scavenging ability under more than 75,0000 plants/hm2; Whole film mulching reduced inhibiting hydroxyl radicals effect, DPPH removal ability and resistance oxygen anion free radical vitality of Jinshu 8 under more than 75,0000 plants/hm2.