| In order to clarify the change law of material production and photosynthetic characteristics of corn with different plastic film mulching in the low temperature and cold area of eastern Jilin Province,Reveal the mechanism of the growth of mulching film.Field trials were conducted in Nandao Village,Songjiang Town,Antu County,Jilin Province from 2018 to 2019,the early-maturing corn variety Longping 702 and the mid-early maturing corn variety Dade 216 were used as test materials,In 2018,four early-maturing varieties + degradable transparent mulching film(L1),early-maturing varieties + non-degradable transparent mulching(L2),early-maturing varieties + non-degradable black film mulching(L3),and early-maturing varieties + no film mulching(LCK)deal with.In 2019,on the basis of the four treatments in2018,middle-early varieties + degradable transparent mulch(D1),middle-early varieties +non-degradable transparent mulch(D2),middle-early varieties + non-degradable black mulch(D3)were added.4 treatments of medium-early maturity varieties + no film mulch(DCK).To study its yield and its constituent factors,dry matter accumulation,dry matter distribution and transportation,nitrogen accumulation,photosynthesis-related parameters and changes in photosynthetic enzyme activity,the main research results are as follows:1.The yields under different mulching treatments are all shown as degradable transparent mulch cover>non-degradable transparent mulch cover>non-degradable black mulch cover>no film,the yields of the two varieties under the three mulching treatment conditions were significantly higher than those of the non-mulching control group.The yield of the two varieties under different mulching conditions was that the yield of transparent film mulching was significantly higher than that of black film mulching.The two-year average output of L1,L2,and L3 is 20.35% higher than that of LCK,and the average output of D1,D2,and D3 is 28.80%higher than that of DCK.The performance of 100-grain weight is consistent with the yield.2.The dry matter accumulation of the whole plant during the maturity stage of the two varieties is as follows: degradable transparent mulching film coverage> non-degradable transparent mulching film coverage> non-degradable black film mulching film coverage> no film,Compared with DCK,the dry matter of D1,D2,and D3 was increased by 24.2%,22.3%,and 19%,respectively.The dry matter of transparent film was significantly higher than that of black film.Accumulation of dry matter after flower,transfer amount of dry matter,transfer rate of dry matter,and contribution to grain of dry matter transportation to the grains of the two varieties showed that the mulching treatment was higher than the non-film treatment.The grain accumulation of nitrogen accumulation in each organ at the maturity stage is consistent with the accumulation of the whole plant.The nitrogen accumulation and distribution ratio of each organ is grain>leaf>stem>sheath>tassel.3.Different mulching treatments can increase the leaf area index of corn plants and the chlorophyll SPAD value of leaves.During the whole growth period of corn,the net photosynthetic rate increased first and then decreased,reaching the maximum 90 days after sowing.The net photosynthetic rate of different varieties at different times is that the net photosynthetic rate under the film treatment is higher than that of the non-film treatment,and the net photosynthetic rate of the two transparent films of different varieties is significantly higher than that of the non-film treatment at each time.Film mulching can increase leaf transpiration rate and stomatal conductance of the two varieties,and reduce the intercellular CO2 concentration of the leaves.The photosynthetic enzyme activities at different times were all expressed as degradable transparent film mulching>non-degradable transparent mulching film>nondegradable black film mulching>no film.Film mulching can effectively enhance the photosynthetic ability of corn leaves.4.The correlation showed that there was a significant positive correlation between yield and corn dry matter accumulation,nitrogen accumulation,nitrogen accumulation,chlorophyll SPAD value,leaf net photosynthetic rate,and Rubp enzyme activity in each time period.In the early stage of maize growth,the dry matter accumulation,nitrogen accumulation,and leaf chlorophyll SPAD values all showed extremely significant correlations.Based on the above analysis,transparent film mulching cultivation can increase corn leaf area index,chlorophyll SPAD value and photosynthetic enzyme activity,thereby increasing the photosynthetic capacity of corn leaves,increasing the material accumulation and nitrogen accumulation of corn,and achieving the effect of increasing yield.Transparent mulching cultivation can effectively improve the limitation of insufficient accumulated temperature in cold areas and low growth period,which can only plant early-maturing varieties,and broaden the range of varieties.The early-maturing varieties in the degradable transparent film mulching configuration are the best stress-resistant and high-yield cultivation mode for corn in cold areas. |
