| Through field experiments,the effects of controlled-release urea(CRU)input on soil water t emperature,nitrogen,enzyme activity,plant growth and nitrogen accumulation under different m ulching patterns were explored,providing theoretical basis and technical support for the efficient use of nitrogen fertilizer and high-yield and efficient cultivation in the mountainous areas of s outhern Ningxia."Xianyu 698" was used as the test material,and the split-zone test design w as adopted,with the mulch mode as the main area,respectively binary mulch M1 and full-film mulch M2;the nitrogen application mode was the secondary area,and the equivalent nitrogen amount(225 kg·hm-2).Under the conditions,set CK:no fertilization,T1:100%conventional ur ea(U)one-time basic application,T2:conventional urea 2/3 basic application,1/3 small trumpet period application,T3:2/3 CRU+1/3 conventional urea was applied in a single base applicatio n.The changes of the CRU input soil water temperature and the spatial and temporal distributi on of inorganic nitrogen under different mulching modes were analyzed.The effects of the abo ve changes on maize nitrogen absorption operation,utilization efficiency and yield.The main f indings are as follows:1.The mulching mode significantly increased the soil temperature on the ridges and furro ws,and M2 was the best,with an average increase of 9.07%compared to M1.The M2T3 is t he best mulching and nitrogen application modes on the ridges;the ridges and grooves are bett er insulated with M2T1 in the early growth period,and the M1T3 is the best in the middle an d late growth period.The path analysis of ground temperature and output shows that the tempe rature increase effect of M1T3 treatment in the period of the big bell contributes the most to t he final output.The mulching mode significantly affected the soil moisture content of 0-60 cm ridges and furrows.M2 on the ridges was the best,which was 26.22%higher than M1;the pe rformance of the furrows was the opposite,with MI being better.In the interaction mode of mu lching and nitrogen application,M2T3 at the flowering stage-mature stage on the ridge was the best,with a water content of 26.3%;the furrow reached the highest 21.16%with M1T3.The mulch of M1 and M2 can increase the water utilization rate by 17.88%and 20.05%respectivel y;the mulch x nitrogen application mode with M1T3 is up to 24.18%,and the precipitation ut ilization rate of this treatment is also up to 24.68%.Path analysis shows that M1T3 at flowerin g stage is beneficial to increase soil moisture and com yield.Nitrogen application mode had no significant effect on soil moisture and temperature on the ridge and furrow.2.Both mulching and nitrogen application modes significantly affect soil nitrogen changes.In the range of 0-80cm,the soil total nitrogen and nitrate nitrogen contents of M2 were signifi cantly higher than that of M1,while the changes of ammonium nitrogen contents of the two tr eatments showed the opposite changes.CRU input can significantly increase the inorganic nitrog en content of each soil layer,of which the total nitrogen,nitrate nitrogen and ammonium nitrog en content of the whole soil layer under the T3 treatment flowering stage-mature stage reached 0.80g·kg-1,24.22mg·kg-1,4.01mg·kg-1,significantly higher than other treatments.Under the full film mulch,the U/CRU combined application(M2T3)under the soil layer of 0-60cm at the fl owering stage-mature stage,the total nitrogen content increased significantly by an average of 106g·kg-1;the binary mulch of the U/CRU.The combined application(M1T3)under the 0-40cm soil layer at the flowering stage-mature stage,the nitrate nitrogen and ammonium nitrogen con tents increased significantly by 60.33mg·kg-1 and 8.29mg·kg-1,respectively.Path analysis shows that M1T3 treatment increased soil inorganic nitrogen during the big trumpet stage,which is co nducive to improving the final yield of spring maize.3.Mulch,nitrogen application mode significantly improves soil urease,phosphatase and pro tease activities.The 0-40cm soil layers are best covered by binary mulch of 0.142mg·g-1·24h-1 a nd 0.217mg·g-1·2h-1,130.03ug·g-1·24h-1;the best nitrogen application mode is T3;the interaction between mulch and nitrogen application is significantly different after the flowering period,the best average activity of M1T3 is 0.156mg·g-1·24h-1,0.269mg·g-1·2h-1,138.62ug·g-1·24h-1.Soil e nzyme activity of 0-20cm soil layer is significantly improved compared to 20-40cm soil layer.Path analysis showed that the increase of M1T3 treatment soil urease,phosphatase and protease activities at flowering and mature stages contributed the most to yield.4.The leaf area index of CRU input peaked at the flowering stage under different mulch modes,and the mulch mode had no significant effect on it.The fertilization mode was the best T3,and the M1T3 best reached 4.96 under the interaction of mulch x nitrogen application mo de.The high-efficiency leaf area also presents an extreme value at the flowering stage,and the mulch mode does not reach a significant level;the nitrogen application mode is the best with T3 to 2894.93cm2,which is 14.74%,3.67%and 3.10%higher than CK,T1 and T2;In the m ode,M1T3 is best to reach 2989.63cm2.5.Logistic dynamic curve of plant dry matter accumulation shows that binary mulch and c ontrolled-release urea treatment can significantly prolong the time for dry matter to reach the m aximum accumulation rate.Among them,T3 compared with CK,T1,T2 treatment Ym increase d by 22.97%,1.06%,4.72%;Vm increased by 73.84%,41.36%,29.53%;Tm extended by 14.29%,6.67%,11.63%.The interaction mode M1T3 can significantly improve the accumulation,di stribution and utilization of corn material and nitrogen,and its post-anthesis material accumulati on is up to 16542.90kg·hm-2,the post-anthesis dry matter transport efficiency is 41.19%,and th e dry matter transport on the grain.The contribution rate is 42.30%;the nitrogen absorption rat e is up to 26.16%,the nitrogen transport amount is 70.68kg·hm-2,the contribution rate of nitro gen operation to the grain is 56.00%,and the nitrogen accumulation after flowering is 110.91k g·hm-2,the nitrogen fertilizer utilization rate reached 39.38%,which was 12.64%,13.49%,6.72%,and 8.81%higher than M1T1,M2T1,M1T2,and M2T2,respectively.The path analysis of soil inorganic nitrogen and plant nitrogen absorption showed that the nitrogen supply and dem and of M1T3 treatment had the highest coincidence,which effectively increased maize yield.6.CRU input significantly increased the yield of spring maize under different mulching mo des,and the yield of M2 was significantly higher than that of M1;the best average of T3 was 14.73t·hm-2 in nitrogen application mode;under the interaction of mulch and nitrogen applicati on mode,The output of M1T3 was significantly increased to 15.13t·hm-2,which was significant ly higher than that of ordinary urea treatment and full-membrane mulch CRU treatment.Thousa nd-grain weight and grain number per spike in M1 treatment were significantly increased by 8.86%and 2.07%compared to M2;nitrogen application mode had a very significant effect on th ousand-grain weight and grain number per ear,with T3 being the best at 283.45g and 600.58 g rains;mulch×nitrogen application mode,M1T3 thousand-grain weight and ear grains number we re significantly higher than other treatments,respectively 289.96g,607.53 grains.It can be seen that the increase in yield is mainly due to the increase in the number of spikelets and the tho usand-grain weight. |
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