KMS Institute of soil and water conservation Chinese Academy of Sciences
|Place of Conferral||北京|
|Keyword||温度 硝态氮 水分 作物生长 免耕 生物炭 地膜覆盖 秸秆覆盖|
1.小麦地2016-2017生长季，传统翻耕配施钾肥（NPK）和添加生物炭（NPB）较传统翻耕（NP）对土壤水分补给与消耗无明显影响。NPK土壤剖面硝态氮存在累积峰，但峰值只有NP的20.2%，硝态氮主要分布在0-100 cm土层；而NPB剖面无硝态氮累积，硝态氮主要分布在0-20 cm土层，两个处理土壤硝态氮累积量在0-300 cm层较NP显著减少了66.0%和73.2%。覆膜处理较NP显著影响土壤水分补给与消耗，传统翻耕配合生育期地膜全覆盖（NPFGT）、休闲期地膜全覆盖（NPFFT）和全年地膜全覆盖（NPFWT）在0-300 cm层水分补给量较NP显著增加32.7%、43.1%和43.5%，而NPFFT水分消耗量较NP显著提高2.0倍。NPFFT和NPFWT土壤剖面硝态氮存在累积峰，但峰值只有NP的77.1%和37.8%，而NPFGT剖面无硝态氮累积。三个处理硝态氮分别主要分布在0-200、0-100和0-20 cm土层，硝态氮累积量较NP显著减少了19.2%、59.7%和78.7%。此外，NPFGT和NPFWT较NP生物量、产量和水分利用效率分别显著增加56.4%和66.3%、20.0%和18.9%及24.3%和15.2%，而NPFFT水分利用效率显著减少22.7%。
2.玉米地2016-2017和2017-2018生长季，土壤水分变化均经过补给、消耗和再补给的过程。第一次水分补给时期（休闲-抽雄期），水分主要在100 cm以下的深层补给，其中免耕配合地膜覆盖（NF）、秸秆覆盖（NS）和秸秆地膜二元覆盖（NSF）水分补给量较免耕（NT）平均显著增加17.1、25.3和31.6 mm。水分消耗时期（抽雄-灌浆期），水分主要在0-200 cm消耗，其中NS、NF、免耕添加生物炭（NB）和NSF水分消耗量较NT平均显著增加19.7、26.4、27.6和41.7 mm。第二次水分补给时期（灌浆-收获期），水分主要在0-100 cm层补给，其中2017-2018生长季NF和NB水分补给量较NT显著提高2.7和6.4倍，NS显著降低75.0%。NS和NB不同时期硝态氮变化主要集中在0-100和200-300 cm，两个生长季收获期硝态氮累积量较NT显著降低26.5%和45.2%，且NS均存在明显的累积峰；NSF和NF硝态氮只在0-40 cm层有明显变化，两个生长季收获期硝态氮累积量较NT显著降低62.5%和70.5%，且均无累积峰。此外，NB生物量和水分利用效率较NT两年平均显著增加18.4%和15.6%；NF和NSF生物量、产量和水分利用效率较NT平均显著增加43.4%和49.2%、43.4%和50.5%及37.2%和44.2%，且氮素吸收、LAI和降雨利用效率均较NT显著提高1.7倍。
再者，2017-2018生长季NS较NT生育前期（0-85天）0-80 cm层土壤温度显著降低1.3-2.1 ℃；而NF较NT显著增加0.6-1.5 ℃。休闲期，NSF、NS、NF蒸散量较NT显著减少12.0、19.3和32.5 mm；而生育期，NB蒸散量较NT显著减少28.4 mm。
The cultivated area in the dry farming tableland area of the Loess Plateau accounts for 1/3 of the total area, which is an important grain-producing area and a typical rain-fed agricultural area in the northwestern region. The main problems faced by agricultural production are less rainfall and uneven seasonal distribution, more fertilization but low utilization rate. Therefore, water and nutrients are the keys to limiting the high and stable yield of crops. In this paper, the continuous cropping system of winter wheat and spring maize in rainfed farmland was selected as the research object. Different conservation tillage measures were set in the Loess Plateau of Wangdonggou small watershed in Changwu County, Shaanxi Province, carried out field experiment for two years. Firstly, 7 treatments were selected in wheat fields and 6 treatments were selected in maize fields to analysis soil nitrate accumulation and water transport in 2016-207. Then, the changes about soil temperature, water content, and NO3--N and crop development of six treatments in maize field were analyzed in 2017-2018. So that the effects of different farmland management measures on soil temperature, water, fertilizer, and crop production were studied to improve water and fertilizer use efficiency and increase crop yield, and to provide a theoretical basis for selecting farmland management measures suitable for sustainable production in the region, the main research results are as follows:
1 In the 2016-2017 growing year, compared with conventional tillage (NP) in the wheat field, NP with potassium fertilizer (NPK) and NP with biochar (NB) had no significant effect on soil water replenishment and consumption. The NO3--N of NPK was concentrated in 0-100 cm, and cumulative peak accounted for only 20.2% of NP. While NB was concentrated in 0-20 cm and had no cumulative peak. And the NO3--N accumulation of them in 0-300 cm significantly decreased 66.0% and 73.2%. Mulching were significantly effected on soil water replenishment and consumption, the water replenishment of NP with plastic film mulching in growing period (NPFGT), plastic film mulching in fallow period (NPFFT), and plastic film mulching in the whole year (NPFWT) significantly increased 32.7%, 43.1%, and 43.5%. while the consumption of NPFFT increased significantly 2.0 times in 0-300 cm compared with NP respectively. The NO3--N of NPFFT, NPFWT, and NPFGT were concentrated in 0-200, 0-100, and 0-20 cm, and cumulative peak of NPFFT and NPFWT accounted for only 77.1% and 37.8% of NP, while NPFGT had no cumulative peak. And the NO3--N accumulation of them in 0-300 cm significantly decreased 19.2%, 59.7%, and 78.7%. In addition, the biomass, yield, and water use efficiency of NPFGT and NPFWT significantly increased 56.4% and 66.3%, 20.0% and 18.9%, and 24.3% and 15.2%, while the water use efficiency of NPFFT significantly decreased 22.7% compared with NP.
NPFGT and NPFWT improved soil water status and significantly increased yield, and NPFGT was the best treatment to reduce the leaching and accumulation of NO3--N. NPB and NPK cannot improve soil water status, but they all effectively reduced the leaching and accumulation of NO3--N. While NPFFT not only significantly reduces water use efficiency and yield, but also fails to alleviate the leaching and accumulation of NO3--N.
2 In the 2016-2017 and 2017-2018 growing year, the soil water had gone through water replenishment, consumption, and recharge. During the first water replenishment period (fallow-tasseling), soil water was mainly replenished to the deep below 100 cm. The replenishment of no-tillage with plastic film mulching (NF), straw mulching (NS), and straw-plastic film mulching (NSF)was significantly increased 17.1, 25.3, and 31.6 mm compared with no-tillage (NT). During the water consumption period (tasseling-filling), soil water was mainly consumed from 0-200 cm. The consumption of NS, NF, NT with biochar (NB), and NSF were significantly increased 19.7, 26.4, 27.6, and 41.7 mm compared with NT. During the second water replenishment period (filling-maturing), soil water was mainly replenished to the deep above 100 cm. The replenishment of NF and NB significantly increased 2.7 and 6.4 times, while NS significantly decreased 75.0% compared with NT in 2017-2018 growing year. The soil NO3--N transport of NS and NB were concentrated in 0-100 and 200-300 cm, which NO3--N accumulation were significantly decreased 26.5% and 45.2% compared with NT in maturing period, and NS had obvious cumulative peaks. While NSF and NF were concentrated in 0-40 cm, which NO3--N accumulation were significantly decreased 62.5% and 70.5%, and had no cumulative peaks. In addition, the biomass and water use efficiency of NB significantly increased 18.4% and 15.6% over the two years compared with NT. And the biomass, yield and water use efficiency of NF and NSF significantly increased 43.4% and 49.2%, 43.4% and 50.5%, and 37.2% and 44.2%, and nitrogen uptake, LAI, and rainfall use efficiency were significantly increased 1.7 times.
Moreover, the soil temperature of NS was decreased 1.3-2.1 ℃ in the early growth period (0-85 day), while NF was increased 0.6- 1.5 ℃ compared with NT in 2017-2018 growing year. And the evapotranspiration of NSF, NS, and NF significantly decreased 12.0, 19.3, and 32.5 mm in fallow period compared with NT, while NB was significantly decreased 28.4 mm in growth period.
Combined with two-year maize field experiment, NS could improve soil water condition but reduced soil temperature, yield did not increase significantly, and it could not effectively alleviate NO3--N leaching and accumulation. NB, NF, and NSF can improve nitrogen utilization, but NB cannot effectively improve soil water and temperature conditions, and the yield increase was not significant, while NF and NSF improved soil temperature, water and crop growth status, it significantly increased water use efficiency and yield.
|MOST Discipline Catalogue||农学::农业资源与环境|
|Table of Contents|
|胡锦昇. 黄土塬区农田管理措施对土壤水氮运移及作物生长的影响[D]. 北京. 中国科学院大学,2019.|
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