| Since 1980 s, the optimized rainfall-harvesting technique has been widely applied and extended in the dryland area. Especially, after continuous development and improvement in practice,the technology named fullmulching on double ridges and sowing in catchment furrows has gradually became the main cultivation technique in rain-fed agriculture area of the Loess Plateau. However, thestudies indicated that some potential negative outcomes such as lower soil enzyme activity and deep soil dry layer has appeared because continuous usage of this technique. In order to improve the sustainability of ridge and furrow rainfall harvesting cultivation technology in semiarid region of the loess plateau, this experiment mainly compared the full mulching on double ridges and sowing in catchment furrows with the full filmmulching on double ridges isolating furrows and sowing in catchment ridges, aimed to choose the best way of tillage.“Jingkai 3”, a local maize variety was used as test experimental. In 2013~2014, field experiment was conducted at field plant genebank in Yuzhong campus of Lanzhou university, and field soil moisture, soil temperature, soil nutrient content, soil enzyme activity, dry matter accumulation of each growth period, yield, water use efficiency, soil quality, climate parameters and related indicators was studied, in order to reveal the sustainability of ridge and furrow rainfall harvesting cultivation technology. Our experiment comprised of five treatments as follows: film mulching on flat in early spring(WFM), full mulching on double ridges and sowing in catchment furrows in early spring(WRM), the full film mulching on double ridges isolating furrows and sowing in catchment ridges in early spring+straw mulching on furrows(MRM), the full film mulching on double ridges isolating furrows and sowing in catchment ridges in early spring+non-mulching on furrows(MRN), non-film mulching(CK). Each treatmentwas arranged randomly with 3 replications. After two growing seasons of experiment, results were as follows:1. Under the ridge and furrow rainfall harvesting cultivation technology, the soil moisture was higher than that before sowing, which benefits for maize seed germination, emergence and growth, and provided a good growth environment for maize later growth. However, in quick growth period of maize, the treatment WRF promoted growth through over-using soil moisture in deep soil under film,but the treatments of MRM and MRN show a good stability.2. Two years of field experiment indicated that the variation trend of soil moisture from 100 to 200 cm between different treatments was not same, and the capacity of water storage of ridge and furrow rainfall harvesting cultivation technology was higher that of flat planting.In the harvesting stage, the capacity of water storage of treatment of WFM was lowest than others, but treatments WFM and MRN was highest, and treatment WFM was second. In two growing years, the water storage of treatment WFM and WRF was both declined. After harvesting in 2013 and 2014, the capacity of water storage was reduced by 89.84 mm and 12.76 mm, 33.12 mm and 26.56 mm, respectively. While, the water storage of treatment MRN and MRM increased by 46.27 mm and 36.32 mm,52.23 mm and 41.48 mm, respectively3. In the two growing seasons, the variation trend of soil temperature across different treatments was same. The rate of temperature increase was recorded as follows: MRN>MRM>CK>WFM>WRF, while the cooling rate under different treatments was same in two growing seasons, and as follows: WRF<WFM<MRN<MRM<CK. So, the cultivation of sowing in catchment ridges makes plants raised temperature faster, and drop in temperature fatly. But, as a whole, the temperature was higher than that of cultivation of sowing in catchment furrows and flat planting. Although the temperature raised quickly with sowing in catchment furrows, but it declined also quickly, which benefited for soli temperature keeping stable and constructs a good water, temperature environment for planting growth.4. The nutrient consumption of each growth period was not same under different treatments. After one growth season, the variation of soil nutrient content and enzyme activity under different soil deep showed differences. After harvest, the soil nutrient content with ridge and furrow rainfall harvesting cultivation technology, declined obviously by comparing with non-mulching planting. Through combining filming mulching and ridge and furrow planting, the soil nutrient use efficiency was significantly improved. The urease activity, catalase activity, acid phosphatase activity and activity of alkaline phosphatase in the 0-40 cm soil layer was improved with ridge and furrow rainfall harvesting cultivation technology. Especially, the full film mulching on double ridges isolating furrows and sowing in catchment ridges technology raised them significantly.5. The study indicated that the effect of the leaf number, leafarea index and biomass accumulation with film mulching technology was not significant difference. But the ridge and furrow rainfall harvesting technology was better than full film mulching on flat.In two growth seasons, the variation trend of leaf number, leafarea index and biomass accumulation with different treatment kept same, and sorted alphabetically by size as follows: WRF>MRM>MRN>WFM>CK. So we found that full mulching on double ridges and sowing in catchment furrows promotes leaf growth of maize significantly, and the full film mulching on double ridges isolating furrows and sowing in catchment ridges was second.6. After harvesting, the increased trend on dry matter accumulation underground during two growth seasons was same, but the increase between the first and second year existed differences. As follows, the underground biomass in first year was higher than that in second year. In the harvesting period of two growth seasons, the above-biomass of treatment WRF reached to 22898.99 kg/ha and 20319.37 kg/ha, respectively. While the treatment of MRM and MRN reached to 23254.25 kg/ha and 21399.85 kg/ha, 21788.26 kg/ha and 20731.10 kg/ha, respectively. So, we found that the full film mulching on double ridges isolating furrows and sowing in catchment ridges has significantly increased the above-biomass accumulation of maize, and the effect of increasing was best by comparing with full mulching on double ridges and sowing in catchment furrows.7. In two growth seasons, the grain yield and water use efficiency of treatments WRF, MRM and MRN were significantly higher than that of the other treatments. In the first year, the grain yield reached to 12863.49 kg/ha, 11611.50 kg/ha and 11294.09 kg/ha, respectively by comparing with the treatment CK(non-film mulching), increased by 134.51%, 111.69 and 105.90%, respectively, and water use efficiency reached to 30.82 kg.hm-2.mm-1, 31.52 kg.hm-2.mm-1 and 31.51 kg.hm-2.mm-1,respectively compared to the treatment of CK(non-film mulching), increased by 116.6% and 121.59, respectively. In the second year, the yield of treatments WRF, MRM and MRN reached to 11175.35 kg/ha, 10181.10 kg/ha and 10605.87 kg/ha, respectively compared with the treatment CK(non-film mulching), increased by 177.81%, 153.10% and 163.66%, respectively, and water use efficiency reached to 27.45 kg.hm-2.mm-1, 27.97 kg.hm-2.mm-1and 29.52 kg.hm-2.mm-1, respectively as comparing to the treatment CK(non-film mulching), increased by 183.28%, 188.65% and 204.64%, respectively. Therefore, the treatment of ridge and furrow rainfall harvesting cultivation technology can promote photosynthetic matter transporting to kernel. By optimizing the yield components enhance the yield, harvesting index and above-ground biomass significantly by comparing with the CK(non-film mulching) of traditional farming. However, the differences were not significant by comparing the full film mulching on double ridges isolating furrows and sowing in catchment ridges with full mulching on double ridges and sowing in catchment furrows. As for water use efficiency, the technology of full film mulching on double ridges isolating furrows and sowing in catchment ridges has shown better advantage. This cultivation pattern produced high production under the drought and slight rain climate conditions, in the meantime, above-ground biomass increased and water use efficiency improved, and it is a win-win situation for agriculture production. |
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