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| DOI：10.13522/j.cnki.ggps. 20180106 |
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| A Drip Fertigation Schedule to Manage Soil Water and Salt in Hot Pepper Field in Hexi Corridor |
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HAN Xiaoyu, WAN Shuqin, LI Xiaobin, KANG Yuehu, FENG Zhiwen
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1.Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographical Sciences and Natural Resources Research, CAS, Beijing 100101, China; 2.University of Chinese Academy of Sciences, Beijing 100049, China; 3.Inner Mongolia Potato E&T Research Center, Inner Mongolia University, Hohhot 010021, China
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| Abstract: |
| 【Objective】Keeping salt in root zone below a threshold is critical to sustaining crop growing and the purpose of this paper is to experimentally investigate the efficacy of using drip fertigation schedule to manage soil water and salt in hot pepper field in Hexi Corridor.【Method】The field experiment was conducted in Bayi Farm at Jinchang city of Gansu province. In the experiment, the soil matric potential at the depth of 20 cm, just below the drip emitter, was controlled higher than -20 kPa. Five fertilizations were examined, which were 20%, 40%, 60%, 80% and 100% of the recommended fertilizer application to the hot peppers in the farm, calculated based on the measured soil nutrients. For each treatment, we measured the growth, yield of the pepper, as well as the distributions of salt and nutrient in soil profile. 【Result】 The two-year experiments found that: ①Salt content in 0~120 cm soil remained almost unchanged and no soil salinity occurred. ② Inorganic nitrogen mainly stayed in the root zone, 0~40 cm, and was low and stable in subsoil below 70 cm; we did not find nitrogen leaching. ③ Both plant height and above-ground fresh weight of the pepper increased with nitrogen application; the yield peaked when 100% of the recommended fertilizer was applied with the associated two-year average being 26 595.8 kg/hm2. ④Increasing fertigation frequency improved both irrigation water use efficiency and fertilizer productivity, with the two-year average irrigation water use efficiency being 5.1 kg/m3 and partial productivity of fertilizer being 30.1 kg/kg.【Conclusion】Keeping soil matric potential at depth of 20 cm, just below the emitter, above -20 kPa can be used as a guidance to manage soil water and salt to safeguard hot pepper production in Hexi Corridor. The fertilizers application should be 100% of the recommended-consisting of N 360 kg/hm2, P2O5 195 kg/hm2 and K2O 375 kg/hm2. |
| Key words: drip fertigation; inorganic nitrogen concentration; irrigation water use efficiency; fertilizer productivity; hot pepper; soil salt |
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