The Effects Of Different Mulching Patterns On Soil Water,Temperature And Maize Growth In Loess Plateau Areas

The loess plateau includes every dry-land agriculture features of northern China, which has been one of the most important areas for grain production. In order to overcome the problems of fragile ecological environment, backward cultivation management, inadequate rainfall and seasonal drought(spring drought), the present study evaluated different mulching and planting patterns in semi-arid areas(Ningxia Pengyang) and semi-humid areas(Shannxi Yangling) in loess plateau from 2012�2015. And the effects of different mulching patterns on soil water, soil temperature, maize growth and yield were well studied. The main obtained results are as follows:1. The effects of different plastic film mulching seasons on soil water and maize yield in the semi-arid area(1) Plastic film mulched during the whole season from autumn in previous year(PAW)reduced soil evaporation during the fallow season by 28.5�39.8% and 36.9�52.6% compared with plastic film mulching from early spring(PSW) and sowing time(PPW) respectively.PAW increased soil water content in the 0�60 cm, 60�120 cm and 120�200 cm layer by 3.43�12.8%, 5.4�9.2% and 4.1�11.2%, compared with PSW, respectively, and 10.0�39.7%, 8.6�11.7% and 7.0�19.7% compared with PPW, respectively.(2) PAW realized redistribution of rainwater during the fallow season and growing season. The potential precipitation use efficiency(PRE) under PAW was 6.0�8.8% and 9.6�15.8% higher than that under PSW and PPW, respectively. The average precipitation use efficiency(PUE) of 2014 and 2015 under PAW increased by 4.0% and 6.0% compared with PSW and PPW, respectively.(3) PAW obviously increased plant height, leaf area and biomass compared with PSW and PPW during seedling�jointing stage of maize. The yield under PAW was 2.4�6.3%, 3.3�9.5% and 44.3�74.6% compared with PSW, PPW and CT, respectively. However the yield increase with PAW was greatly influenced by precipitation, which was not significant compared with PSW and PPW when the fallow season or growing season was rainy.2. The effects of different mulching materials on soil environment and maize growth in the semi-arid area(1) PAW increased soil water storage in the 0�20 cm layer, but the soil water consume gradually removed to deeper soil layer with the development of maize growth. The soil water utilization degree was 5.0 times compared with CT. The soil water variation of degradable film mulched during the whole season from autumn in previous year(BAW) was similar with PAW, but BAW reduced soil water consumption compared with PAW, and the soil water supply capacity at the end of season(WSC) under BAW was 17.0 mm and 20.5 mm higher compared with PAW during 2014 and 2015, respectively. SAW showed better soil water preserving and increasing effects, and it had lower soil water consumption and smaller soil water variable coefficient. Thus the soil water was more stable under SAW compared with other treatments.(2) PAW and BAW increased the amplitude of soil temperature warming, and decreased the amplitude of temperature cooling. The soil increasing effect of PAW and BAW was mainly showed in 0�60 days and 0�30 days after sowing, respectively. The soil temperature in the 5 cm, 10�15 cm and 20�25 cm under BAW was 0.6�4.3�C ? 0.7�4.1�C and 0.5�3.0�C lower than that under PAW, respectively, and the accumulated temperature during the growing season under BAW was decreased by 232.3�300.8�C compared with PAW. SAW both reduced the soil temperature warming and cooling amplitude, the soil temperature in the5 cm, 10�15 cm and 20�25 cm under SAW was 0.6�4.9�C, 0.5�3.5�C and 0.3�2.5�C lower than that under CT respectively, and the accumulated temperature during the growing season under SAW was decreased by 172.5�271.4�C compared with CT.(3) PAW and BAW increased the content of soil available N, P and K. In the 0�20 cm,PAW increased soil available N, P and K by 7.1%, 28.3% and 21.2% compared with CT,respectively, and those values under BAW were increased by 7.5%, 17.1% and 21.1%compared with CT, respectively. PAW enhanced the consumption of soil organic matter, and decreased content of soil total N and P. SAW increased soil available N, P and soil organic matter by 11.4%, 14.7% and 15.3% compared with CT, respectively. Straw mulching had a great influence on soil potassium, the available K and total K under SAW was 40.7% and10.15% higher than that under CT.(4) PAW and BAW obviously shortened the maize growth and development progress,increased maize plant height, leaf area, stem diameter and dry matter accumulation, which was most significantly during the seedling stage and jointing stage. The maximum cumulative speed of dry matter accumulation with PAW was 1.7 g/d and 1.6 g/d higher than that with BAW and CT. And PAW also increased the amount and the efficiency of nitrogen nutrient translocation in leaf, stem and sheath of maize. The yield with PAW increased by 18.1�31.4%and 44.3�74.6% compared with BAW and CT, respectively.(5) SAW delayed the maize growth and development, the maturity stage with SAW was8 days and 4 days later compared with CT during 2013 and 2015, respectively. The average maximum cumulative speed of dry matter accumulation and yield with SAW were 1.2 g/d and16.7�33.2% lower than those with CT, respectively. Straw mulching only during the fallow season(SAF) did not preserve the soil water during the growing season, and had no significant effects on maize yield compared with CT. Liquid mulching during the whole season from autumn in previous year(LAW) had no significant effects on soil water, soil temperature and yield, which should be used with caution in field crops. SAW, SAF and LAW reduced the input-output ratio, and reduced the net income by 7127.9 Yuan /hm2, 1494.4Yuan /hm2 and 1917.2 Yuan /hm2 compared with CT, respectively.3. The effects of ridge and furrow alternation for drought resisting sowing technology on soil water and maize growth in the semi-arid area(1) Under alternating ridges and furrows where only the ridges were mulched with plastic film(PRF planting) and alternating ridges and furrows where only the ridges were mulched with plastic film(SRF planting), the soil water permeated from furrow to ridge after raining. And the soil water content in the 0�40 cm layer under the ridges was higher than that under the furrows and besides the furrows and ridges since early spring(March).(2) Alternated PRF(PRF1) increased soil water in the 0�40 cm layer by 11.5% and25.3% compared with PRF without alternation(PRF2) and CT, respectively. Alternated SRF(SRF1) increased soil water in the 0�40 cm layer by 9.6% and 14.4% compared with SRF without alternation(SRF2) and CT, respectively. PRF1 was superior to SRF1, which was a useful method for drought resisting sowing.(3) With the maize growth and development, the soil water under PRF1 and SRF1 was not significantly higher compared with PRF2 and SRF2, accordingly. The spring drought was not serous during the experiment year, and the effects of ridge and furrow alternation on maize growth, yield and water use efficiency(WUE) were not significan. The effects under PRF on water harvesting and retaining, and soil temperature warming were significantly than those under SRF. The average yield with PRF increased by 28.8% and 31.7% compared with SRF and CT, respectively(P < 0.05); and the average WUE with PRF increased by 25.3%and 25.3% compared with SRF and CT, respectively(P < 0.05). The maize growth and development, and yield and WUE had no significant differences between SRF and CT.4. The effects of different mulching patterns on soil water, temperature and maize growth in the semi-humid area(1) Plastic film(PAW-Y), straw(SAW-Y) and PRF(PRF-Y) mulching during the whole season from autumn in the previous year effectively increased soil water storage at sowingtime compared with CT-Y. With abnormal highly rainfall(161.8 mm), PAW-Y reduced rainwater infiltration and rainfall storage efficiency during the fallow season(RSF) compared with SAW-Y and PRF-Y. SAW-Y and PFR-Y increased soil water storage compared with PRF-Y and CT-Y. PRF-Y enhanced soil water consumption, and decreased soil water storage in the 0�100 cm and 100�200 cm during the middle and latter growth stage of maize(P <0.05).(2) PAW-Y and PRF-Y increased soil temperature by 4.9�C and 1.4�C compared with CT-Y, which promoted maize growth and development. SAW-Y decreased soil temperature by 2.0�C compared with CT-Y, which delayed the maize growth and development progress.The maximum cumulative speed of plant height, leaf area and dry matter accumulation with PAW-Y was 0.86 cm/d, 4.9 cm2/d and 0.3 g/d higher than those with PRF-Y, and was 1.9cm/d, 3.0 cm2/d and 0.8 g/d higher than those with CT-Y. The maximum cumulative speed of plant height, leaf area and dry matter accumulation with SAW-Y was 0.1 cm/d, 3.0 cm2/d and0.2 g/d higher than those with CT-Y.(3) The yield with PAW-Y and PRF-Y increased by 13.9% and 8.8% compared with CTY. Whereas, the yield with SAW-Y decreased by 7.7% compared with CT-Y, of which application had certain risks on in semi-humid areas. SRF mulching during the whole season from autumn in the previous year(SRF-Y) had no significant effects on maize growth and development, and yield compared with CT-Y(P > 0.05). The yield difference between PRF-Y and PAW-Y was not significant(P > 0.05). PRF-Y increased WUE by 10.9% and decreased WUC by 9.0% compared with PAW-Y, respectively(P < 0.05), which was in favor of resisting the droughts during the middle growing stage of maize. Thus, PRF-Y was a usefull method for increasing and stabilizing crop yields in semi-humid areas.