辽西地区坡耕地垄膜沟种对土壤侵蚀和作物产量的影响

Effect of Technique of Ridge Film Mulching and Furrow Seeding on Soil Erosion and Crop Yield on Sloping Farmland in Western Liaoning

【目的】为了充分有效地利用辽西地区有限的自然降雨,减少坡耕地水土流失,提高水土资源利用率,促进作物稳产高产,在辽西地区坡耕地进行了不同耕种模式研究。【方法】2012—2015年在辽宁省农业科学院阜新旱农试验区进行,试验采用径流小区定位观测的方法,研究天然降雨条件下坡耕地不同耕种模式对土壤侵蚀、土壤水分和作物产量的影响。径流小区长15 m,宽4 m。试验为双因素裂区设计,主区为坡度,设5°和10°两个坡度,副区为种植模式,分设传统种植(CK,等高土沟土垄)、等高垄膜沟秸秆种植(T1)、等高垄膜沟种(T2)3种处理,3次重复。垄膜沟种沟宽60 cm,垄宽40 cm,垄高10—12 cm。供试作物为谷子和玉米,轮作种植。【结果】垄膜沟秸秆和垄膜沟种可有效减少和防止水土流失。4年间,5°坡对照总径流量为512.7m3·hm^(-2),总侵蚀量为4 561.3 kg·hm-2,T1处理和T2处理未发生土壤侵蚀;10°坡T1处理总径流量和总侵蚀量较10°坡对照分别减少81.71%和96.17%,T2处理较对照分别减少56.92%和95.15%,10°坡T1处理总径流量和总侵蚀量较T2处理分别减少57.54%和21.05%。垄膜沟秸秆和垄膜沟种较对照减少侵蚀量的同时可明显减少侵蚀泥沙中的养分流失量。随着坡度的增大,径流量和侵蚀量都随之增加,同时垄膜沟秸秆和垄膜沟种防蚀效果相对减弱。4年平均土壤水分,坡度间由5°坡到10°坡呈降低的趋势,但差异不显著;种植方式间垄膜沟秸秆和垄膜沟种与对照差异极显著,较对照分别高出1.68和1.45个百分点。对谷子而言,无论丰水年(2012年)或干旱年(2014年),垄膜沟秸秆和垄膜沟种较对照都表现出极显著的增墒效果;对玉米而言,平水年(2013年)垄膜沟秸秆和垄膜沟种较对照未表现出显著的增墒效果,干旱年(2015年)增墒效果极显著。4年平均产量,坡度间由5°坡到10°坡呈降低的趋势,但差异不显著。种植方式间垄膜沟秸秆与对照及垄膜沟种差异极显著,分别增产25.59%和10.68%,同时垄膜沟种与对照产量差异极显著,比对照增产13.47%。其中2012年和2014年,谷子垄膜沟种较对照增产不显著,垄膜沟秸秆较对照增产显著,分别增产24.75%和74.58%;2013年和2015年,玉米垄膜沟秸秆和垄膜沟种较对照增产极显著,垄膜沟秸秆较对照分别增产11.29%和54.39%,垄膜沟种较对照分别增产5.05%和51.81%。干旱年份,垄膜沟秸秆(谷子,玉米)和垄膜沟种(玉米)增产效果尤为显著。【结论】通过连续4年的旱坡耕地垄膜沟种试验,明晰了该技术模式在辽西半干旱地区的防蚀、集雨、增墒、增产效果,有效减轻干旱缺水和水土流失对坡耕地作物生长所造成的不利影响,丰富了辽西半干旱地区旱作集水农业的理论基础。通过该项技术的推广应用,可有效提高该区水土资源利用率,保护坡耕地质量,提升坡耕地粮食综合生产能力,使作物高产,促进该区旱作农业健康、可持续发展。从防蚀、集水、增墒、增产等角度考虑,垄膜沟秸秆耕种模式比较适宜于辽西半干旱区坡耕地。

[ Objective] In order to make full use of the limited natural rainfall, decrease soil loss from sloping farmland, protect water and soil resources of dry farming area and promote high and stable yield of crops, the study of different styles of farming is carried out on sloping farmland in Western Liaoning. [Method] Two factors split plot deslgn was used to examine the effects of different farming types on soil erosion, soil water and yield in sloping farmland and the study was carried out by runoff plots under natural rainfall from 2012 to 2015 in dry farming experimental area in Liaoning Academy of Agricultural Sciences at Fuxin. The runoff plot was 15 m and 6 m in length and width and the area was 60 m^2. The main plot was a sloping land with slopes of 5°and 10° and split plot was crop planting patterns, the designed patterns were traditional cultivation（CK, contour ridge and furrow planting, ridge and furrow were uncovered）, ridge film mulching and furrow straw mulching（T1）, ridge film mulching and furrow seeding（furrow was uncovered, T2）. The study was repeated three times. Ridges and furrows of ridge film mulching and furrow seeding were in opposite arrangement, furrow width was 60 cm and ridge width was 40 cm, ridge height was 10-12 cm. The ridge was a rain collecting area. The furrow, which was planted with two lines of crop, was a planting area. The experimental crops were millet and maize and rotated.[ Result]The ridge film mulching and furrow straw mulching and ridge film mulching and furrow seeding could effectively reduce and prevent water and soil erosion. In four years, the total runoff and total erosion amount of the CK were 512.7 m^3·hm^2, 4 561.3 kg·hm^2 and T1, T2 did not occur soil erosion under five-degree slope. The total runoff and total erosion amount ofT1 were reduced by 81.71% and 96.17% and that ofT2 were reduced by 56.92% and 95.15% compared with the CK, and that of T1 were reduced by 57.54% and 21.05% compared with T2, T1 and T2 would reduce the amount of lost nutrients in sediment compared with the CK under ten-degree slope. The results showed that runoff and erosion amount increased in accordance with increasing of gradient and the effect of anti-erosion of TI, T2 would weaken along with slope increasing. There was no significant difference between the five-degree slope and ten-degree on four years＇ average soil water, which had a reducing trend with slope increasing. The effect of T1, T2 on mean soil water reached very significant level as a whole compared with CK and mean soil water of T1, T2 was 1.68 and 1.45 percentage points higher than that of CK. The effect of T1, T2 on increasing moisture reached very significant level compared with CK to millet regardless of high flow year or dry year and that ofT1, T2 on increasing moisture to maize was not significant in normal year and very significant in special dry year. There was no significant difference between five-degree slope and ten-degree slope in four years＇ average yield, which had a reducing trend with slope increasing. The effect of T1 on the average production reached very significant level increasing by 25.59% and 10.68% compared with CK and T2, and there was a significant difference between T2 and CK and the average production of T2 increased by 13.47% compared with CK. The effect of yield increasing of T2 was insignificant compared with CK and that of T1, which increased by 24.75% and 74.58%, was significant compared with CK for millet in 2012, 2014. The effect ofT1, which the yield of maize increased by 11.29% and 54.39%, and T2, which increased by 5.05% and 51.81%, on the production reached very significant level compared with CK in 2013 and 2015. The effects of yield increasing of ridge film mulching and furrow straw mulching （millet, maize） and ridge film mulching and furrow seeding （maize） were particularly significant in dry year. [ Conclusion] The effect of micro-rainwater-collecting planting mode by ridge film mulching and furrow seeding in dry sloping farmland on rainwater harvesting, water storage, soil moisture conservation and anti-erosion was definite after 4 years of study in semi-arid region in Liaoxi area. The technique could mitigate the negative impact of drought and soil erosion on crop growth and enriched the theoretical basis of the rain-harvesting agriculture of dry farming in the area. By application and dissemination of the technique, it could improve soil and water resources utilization, protect quality of cultivated land and promote overall grain production capability on sloping farmland and facilitate stable and high yield of crop and healthy and sustainable development of dry farming in the area. It could be seen that the ridge film mulching and furrow straw mulching would be suitable for dry sloping land in Western Liaoning from the point of anti-erosion, catchment, increasing soil moisture, increasing production. The study has filled the gaps in the study of this subject in western Liaoning and provided important references for development of the rain-harvesting agriculture of dry farming in the North of China.