【作者】 张金霞；

【导师】 成自勇；

【作者基本信息】 甘肃农业大学 ， 水土保持与荒漠化防治， 2013， 博士

【摘要】 2011年和2012年连续2年,在甘肃省水利科学研究院民勤试验站布置了碎麦秸垫式膜上灌大田试验,试验系统研究了碎麦秸垫式膜上灌在西北旱区高效用水机理、对西北旱区特色经济作物的生长、产量、土壤环境的影响机制。试验选择覆盖方式和灌水定额两个控制因素,采用双因素完全随机试验设计。覆盖方式设有四个水平：无覆盖(N),秸秆覆盖(S),地膜覆盖(F),碎麦秸垫膜覆盖(SF)；灌水定额设有高(H)、中(M)、低(L)三个水平,即：H:900n3/hm2,M:750m3/hm2,L:600,3/hm2;共形成4x3=12个处理水平,重复3次。通过连续两年的田间试验,主要得出以下主要结论：(1)覆盖方式对作物出苗率的影响极显著(P<0.01)。2011年向日葵试验结果表明,碎麦秸垫膜覆盖(SF)的出苗率比S的提高了14.33%,比无覆盖(N)处理提高了49.32%。2012年玉米试验结果表明,碎麦秸垫膜覆盖(SF)的玉米出苗率比秸秆覆盖(S)的提高了49.50%,比无覆盖(N)的提高了21.36%。总之,碎麦秸垫膜覆盖(SF)对出苗率的影响接近地膜覆盖(F)的,远远高于秸秆覆盖(S)和无覆盖的(N)。故在西北干旱区利用碎麦秸垫膜覆盖(SF)技术可以解决保护性耕作技术中秸秆覆盖(S)的由于土壤温度过低导致的“出苗率低”等问题。(2)覆盖方式对2011年向日葵株高、茎粗、产量及其构成因素、产量性状、收获指数的影响极其显著(P<0.01)。其中碎麦秸垫膜覆盖(SF)的茎粗、百粒重最高,地膜覆盖(F)次之；地膜覆盖(F)的株高、冠干重、茎干重、叶干重、单株生物量、单株粒重、生物产量、籽粒产量最优,碎麦秸垫膜覆盖(SF)的次之。灌水定额对株高、茎粗的主效应在一水灌溉前不显著；一水灌溉后显著；对产量及构成要素、产量性状、收获指数的影响差异不显著。不同的覆盖方式与不同的灌水定额的组合的交互作用对产量及构成要素、产量性状都不显著(P>0.05),对收获指数的影响显著(P<0.05)。从向日葵株高、茎粗、产量及其构成因素、产量性状、收获指数的影响结果考虑,FM.SFM为最佳组合,即地膜覆盖与灌水定额为M、碎麦秸垫膜覆盖与灌水定额为M的组合为最佳组合。(3)覆盖方式对玉米株高、茎粗、产量及其构成因素、产量性状、收获指数的主效应极显著(P<0.01)。覆盖方式各水平上的茎粗均值差异极显著(P<0.01),大小次序是：SF>S>F>N,SF的茎粗比N、S、F分别增加2.20mm、0.26mm、0.93mm.SF与N、S之间差异极显著(P<0.01),比N、S的籽粒产量分别高3444.72kg/hm2、4415.79kg/hm2。覆盖方式对穗长、秃顶长的主效应显著(P<0.05),对玉米收获期穗粗、穗行数、穗粒重的主效应不显著(P>0.05)。可见,碎麦秸垫膜覆盖(SF)与地膜覆盖(F)对玉米产量及构成要素的影响无差异。灌水定额对玉米株高、茎粗、产量及其构成因素、产量性状、收获指数的主效应不显著(P>0.05)。覆盖方式与灌水定额的交互作用对玉米株高、茎粗、产量及其构成因素、产量性状、收获指数有一定的显著度。综合考虑以上因素,最佳组合SFM,FM次之。(4)覆盖方式和灌水定额对0～120cm土壤含水量的主效应在一水灌溉前不显著,在一水灌溉后显著。碎麦秸垫膜覆盖(SF)中的土壤含水量总体优于地膜覆盖的(F)；SF的初始值稍低于F的,播种后25天时田间土壤含水量显示SF中土壤水分最高,在播种前低于F到现在高于F,保墒效果优于F和S,是因为具有地膜、秸秆双重保墒作用。灌水定额较高(H)的处理土壤水分较高,灌水定额中等(M)的处理次之,灌水定额较低(L)的土壤水分含量最小。这主要是因为灌水时灌水定额不同所导致的。故从土壤保墒效果来看,组合SFH的效果最佳,SFM次之。(5)从横向时间轴来看,各覆盖方式的0-25cm土壤温度和气温日变化都呈现出随深度增加而逐渐滞后的趋势。无论哪种覆盖方式,峰值均出现在地表处。地膜覆盖(F)有增温作用,使得其峰值出现的时间较无覆盖处理提前1h,而碎麦秸垫膜覆盖(SF)和秸秆覆盖(S)中的秸秆具有降温作用,导致其峰值滞后1h出现。而碎麦秸垫膜覆盖(SF)中的地膜又具有增温效应,使其峰值比秸秆覆盖(S)的高出7℃。从温度变化范围上来看,同峰值的出现一样,各个覆盖方式的温域的最宽值都出现在地表处。各覆盖方式中,地膜覆盖(F)的增温效应导致地膜覆盖后温域比无覆盖处理(N)的宽,碎麦秸垫膜覆盖(SF)和秸秆覆盖(S)的减温效应使其温域变窄。碎麦秸垫膜覆盖(SF)中地膜的增温作用又使得其温域比秸秆覆盖(S)宽7℃。从深度上来看,温度的变化有早、中、晚三种类型：早晨(6：00-7：00),土壤温度随着深度的增加而增加,表层低、底层高呈地底辐射型；中午(8：00～16：00),土壤温度在地表处最高,属地表辐射型；傍晚(17：00～20：00),土壤温度的峰值出现在5cm或10cm处,为中间辐射型。在同一天内,土壤温度呈现出低——高——低的单峰循环规律。0-25cm深度的土壤温度自作物播种后开始到6月中旬都表现出上升的趋势,6月中旬以后各个深度层次的土壤温度都趋于稳定。碎麦秸垫膜覆盖(SF)与无覆盖处理(N)、地膜覆盖(F)的相比,秸秆阻隔了太阳的直接辐射,具有秸秆覆盖(S)的降温效应；与秸秆覆盖(S)相比,又具有地膜的升温作用。(6)在作物生育期期,各覆盖方式都具有改善0-40cm土层的土壤容重的作用。N、S、SF具有降低0-10cm土层的土壤容重、增加土壤总孔度的作用,而F具有增加0-10cm土层的土壤容重、减小土壤总孔度的作用。在土壤耕层(0-40cm)范围内,与N相比,SF具有土壤容重小、总孔度大的特点,而F、S具有容重大、总孔度小的特点。说明在碎麦秸垫式膜上灌条件下能改善土壤结构和孔隙度,有利于作物的根系生长。(7)2011年向日葵田间,各覆盖方式的0～120cm土壤pH值随着土壤层次的加深有递减的趋势,SF具有降低0-30cm土壤pH值的作用,SF的0-30cm土层的土壤pH值比N、S、F分别降低了3.51%、2.15%、3.69%。2012年玉米田间,各覆盖方式的0-120cm的平均土壤pH值随着生育进程的推进呈现出明显降低的趋势。有覆盖处理中,SF的pH值最小,F的最大,这是因为SF中的碎秸秆的降解过程和根系的分泌物使得土壤pH值降低。这说明碎麦秸垫式膜上灌可明显降低表层土壤的pH值,防止土壤次生盐碱化,使得灌区土地荒漠化得到遏制,土壤环境进一步得到改善。在向日葵和玉米苗期,由于田间土壤裸露多,蒸发强烈,各覆盖方式的土壤盐分都存在不同程度的表聚现象,0-5cm处地膜覆盖(F)的土壤盐分表聚最明显。在整个生育期内,盐分的表聚现象随着生育期的推进逐渐减弱；碎麦秸垫膜覆盖(SF)较明显地抑制了0-5cm的土壤盐分积聚,地膜覆盖(F)却明显使得表层土壤的累积盐分增加。从整个剖面上看,0-120cm土壤的含盐结构变化显著,地膜覆盖(F)具有增加土壤盐分含量的作用,碎麦秸垫膜覆盖(SF)具有脱盐的作用。这是由于播种时灌水后,SF的保墒效果好,表层土壤的含水量大,土层中的盐分随水分向下运动的多,下层内的盐分冲洗量则因水分的减少而减少。这样盐分离开作物主要根系层,有利于作物根系的生长。故碎麦秸垫式膜上灌条件下种植食用向日葵和玉米可以明显抑制表层土壤水溶性总盐的积聚,使得农田土壤环境进一步得到改善,灌区的荒漠化防治得到更有效的控制。(8)向日葵田间0～120cm剖面上HCO3含量呈“中间大、两头小的趋势”。碎麦秸垫式(SF)膜上灌可以降低耕层(0-30cm)土壤中HC03含量,增加深层土壤(60～100cm)中HC03含量。在向日葵苗期,N、S、F在0-5cm土层内Cl、SO4含量有积聚现象,尤其是F的表聚现象最明显；而SF具有抑制Cl、SO42在表层积聚的作用。麦秸垫膜式膜上灌可以降低耕层Cl、SO42含量、增加中下层Cl、SO42含量,这主要是SF的双重保墒作用使得上层土壤中的Cl、SO42被往中下层淋洗的结果。(9)随着向日葵生育期的推进,各覆盖方式的0～120cm土层中Ca2+、Mg2+含量基本呈下降趋势；F具有加速耕层(0-40cm)土壤中Ca2+、Mg2+流失的作用,而S、SF具有抑制耕层土壤中Ca2+、Mg2+含量降低的作用。可能原因是秸秆覆盖、碎麦秸垫膜覆盖后由于作物根系呼吸、根系分泌物以及碎麦秸和收获后作物根系的腐烂分解,使得pH值降低,抑制了固定态钙、镁溶解性降低。SF的30-60cm土壤Ca2+含量表现出在苗期至开花期下降缓慢、开花至收获期回升快的趋势；而F表现出下降速度快、回升慢的特征。向日葵田间0～120cm土壤剖面中,K+含量特别少。在0～10cm土层内有积聚现象,尤其是S、SF中0-5cm土层较明显。在向日葵苗期,N、S、F中0-5cm土壤Na+含量有明显积聚现象,尤其是F处理,而SF却抑制了土壤Na+含量在表层积聚；SF处理的40-60cm土壤中Na+含量明显增加,这是SF将表层和耕层土壤Na+向下淋洗的缘故。到开花期和收获期时,60～120cm土壤Na+含量明显上升,是因为SF的淋洗效果更为明显。SF并没有大幅度降低Na+含量而是调整了Na+在土壤剖面上的分布。从土壤深度方向来看,0-30cm的土壤SAR较小,中间层30-60cm的土壤SAR最大,深层(60～120cm)的介于前两者之间。这一方面是由于上层Na+淋溶到中下层而使中下层Na+含量增加,另一方面是中下层Ca2+和Mg2+含量下降的结果。碎麦秸垫式膜上灌(SF)条件下,土壤表层(0-5cm)和耕层(0-30cm)土壤SAR较其他处理明显减低。这是因为SF中0-5cm土壤中可溶性Na+的比例下降,同时Ca2+和Mg2+的比例则升高。而SF中30～120cm土壤SAR有增大的趋势,说明中下层土壤中可溶性Na+的比例增加了,而Ca2+和Mg2+的比例则相应降低了。由此可以看出,碎麦秸垫式膜上灌(SF)会使阳离子的组成在整个剖面上发生了改变,使得有益于作物的盐分离子积聚、有害于作物的盐分离子被淋洗,这会为西北旱区土壤环境改善、土壤盐碱化和灌区荒漠化防治起到一定的积极作用。更多还原

【Abstract】 In order to research high efficient water use mechanism and soil environmental effects of inthe northwest Arid Regions, China, a combination of mulch means and irrigation experimentswere conducted during two consecutive years of2011and2012, at Minqin Experimental Station,Gansu Hydraulic Research Institute, in Minqin city, Gansu, China. The experiments followed acompletely randomized double factors design with four coverage levels: no coverage (N), strawmulching (S), plastic film mulching (F), crushed wheat straw padding plastic film mulching (SF);and three irrigation quota levels: H,900m3/hm2; M,750m3/hm2; L,600m3/hm2. There are12treatments, repeating3times. The main results are as follows.(1) Mulch means significantly affected crop emergence rate (P<0.01). The experiment aboutsunflower emergence rate in2011showed that, SF was increased by14.33%with S, and49.32%with N. In2012, corn test results show that, SF was higher49.50%than S,21.36%than N. Inshort, the emergence rate with SF was close to with F, far higher than S and N. So, SF can be usedto solve the question "low emergence rate" with S in the northwest Arid Regions, China.(2) Mulching means significantly affected the sunflowers’ height, stem diameter, productionincluding its component factors, characters, harvest index in2011(P0.01) sunflowers plantedwith SF means have the widest stem diameter and the heaviest100kernel weight, and those withF means follows. However, sunflowers in plastic film mulching were the best in plant height, dryweight of root, stem and leaf, single plant biomass and grain weight, biological yield, grain yieldwhile sunflowers with F means take the second place. Irrigation quota doesn’t have a remarkablemain effect on plant height and stem diameter before the irrigation whereas it does after theirrigation. The interaction between different mulching means and different irrigation quota leveldoesn’t show a significant effect on the production and its components, characters (P0.05)while it exerts a significant effect on the harvest index. All factors including plant height, stemdiameter, production and component factors, characters, harvest index of production considered,FM, SFM are the optimal portfolios, that is plastic film mulching and M irrigation quota,crushed wheat straw padding plastic film and M irrigation quota.(3) Mulching means significantly affected the corns’ height, stem diameter, productionincluding its component factors, characters, harvest index(P0.01).The difference in mean value of stem diameter with different mulching means was very significant(P0.01), the sequence being SF S F N. The stem diameter with SF increased by2.20mm0.26mm0.93mm respectively, compared with those with N S F. There is a significantdifference between SF and N,S (P0.01) with the production of kernel being3444.72kg/hm24415.79kg/hm2higher than that with N, S respectively. The main effect of mulching means onear length, baldhead length was significant (P0.05) while the main effect on ear diameter, rowand weight was not significant (P0.05). Therefore, it can be concluded that crushed wheat strawpadding plastic film and plastic film mulching don’t have an impact corn production and itscomponent factors. The main effect of irrigation quota level on corn plant height, stem diameterand production including its component factors, characters, harvest index was not great. Theinteraction between different mulching means and different irrigation quota level did show somesignificant effect on the production and its components, characters and harvest index. Consideringthe above factors, SFM is the optimal portfolio and FM takes the second place. (4) The main effect of mulching means and irrigation quota level on water content of0~120cm soil was not significant before irrigation while significant after irrigation. The overallsoil water content of crushed wheat straw padding plastic film was greater that of plastic filmmulching. The initial value of SF was a bit lower than that of F. The soil water content with SFwas the highest after planting25days. The reason for good water conservation effectiveness wasdue to the double effect of plastic film and straws. The higher irrigation level (H) has the higherwater content and the medium irrigation level (M) follows, the lower (L), the last, which was dueto different irrigation level. Hence, concerning the water conservation effect, SFH is the best andSFM takes the second place.(5) In terms of the horizontal time axis, daily variation of the soil temperature and airtemperature of0~25cm soil with different mulching means showed a trend of a gradual increasewith depth first and then a gradual retardation. Regardless of the mulching means, the peak valuealways occurred at the surface. The peak value of plastic film mulching (F)with a warming effectemerged one hour earlier than that of peak no mulching treatment while the peak value of crushedwheat straw padding (SF) and straw mulching (S) with a cooling effect was one hour late. Thefilm of crushed wheat straw padding plastic film mulching (SF) had a warming effect, so its peakwas t7higher than that of straw mulching (S). Like the peak value, the widest breadth value ofthe temperature range for every mulching means appears on the surface. The temperature range ofplastic film mulching (F) with a warming effect was wider than that of no coverage (N); Thetemperature range of crushed wheat straw padding plastic film mulching (SF) and straw mulching(S) was narrower because of their cooling effect. The temperature range of crushed wheat strawpadding plastic film mulching (SF) was7wider than that of straw mulching (S). The change intemperature has three types: in the morning (6:00~7:00), soil temperature increased with anincrease of depth, lower on the surface, and higher in underground; At noon (8:00~16:00), thehighest soil temperature emerge at the surface, the surface radiant; Evening (17:00~20:00), soiltemperature peak appeared in5cm and10cm, the middle radiant. On the same day, the soiltemperature presents the low-high-low unimodal cycle. Soil temperature of0to25cm depthfrom the middle of June after planting showed a rising trend, and after that the temperature isstable. Chopped straw mat film covering (SF) and no cover processing (N),(F) of plastic filmmulching, straw blocking the sun’s radiation directly, with straw mulching (S) cooling effect;Compared with straw plastic film mulching (F)and no coverage(N), the crushed wheat strawpadding plastic film mulching (SF) stopped solar direct radiation and has a cooling effect(6) In the crop growth period, mulch means improved soil bulk density in0-40cm soil layer.N, S and SF could reduce soil bulk density and increase soil total porosity increased soil totalporosity in0-10cm soil layer, while F increased the soil bulk density and decreased soil totalporosity. Compared with N, SF had the characteristics of low soil bulk density and high totalporosity in the topsoil (0~40cm), while F and S had those of high soil bulk density, low soil totalporosity. It showed that SF could improve the soil structure and porosity, which was beneficial tocrop root growth.(7) With the soil depth in0~120cm profile, soil pH value of mulch means decreased at thesunflower field in2011. SF could reduce the soil pH value in0~30cm. Compared with N, S and F,the soil pH value were decreased respectively by3.51%,2.15%and3.69%. In2012, at the cornfield, with the advance of the corn growth, the average soil pH value of mulch means in0~120cmshowed an obvious decreasing trend. Among mulch means, pH in SF was the minimum, and that of F was the maximum. This is results that crushed straw degradation process and root exudatesdecreased the soil pH value. This showed that SF could significantly reduce soil pH value in thesoil surface, prevented soil secondary salinization, which made the desertification of irrigationdistrict contained and the soil environment further improved. In seedling sunflower and maize, forthe many exposed field and strong evaporation, mulch means aggregated soil salinity in soilsurface with different degree, especially in0~5cm with F. In the whole growth period, saltaccumulation in surface weakened with the progress of growth period gradually; SF significantlyinhibited salt accumulation in0~5cm of soil, but F apparently made salt accumulation increase insurface soil. From the profile view, salt structure changed significantly in0~120cm of soil, and Fincreased soil salt content, while SF had the role of desalination. This is because after sowingirrigation SF had good water retention effects, made soil water content fuller, get soil salt movedown with water, and the less moisture the lower salinity irrigation in the lower layer. In this way,salinity leaving crops root zone is conducive to the growth of crop roots. So, Planting sunlowerand corn with SF could obviously inhibit soil soluble salt accumulation into the surface, made thefarmland soil environment improved further, and more effectively prevented and controlled thedesertification of irrigation district.(8) The HCO-3content at0~120cm soil in sunflower field showed the trend of "big in themiddle, small in both ends". SF can reduce the HCO-3content in topsoil (0~30cm), and increasedit in deep soil (60~100cm). In sunflower seedling stage, N, S, F accumulated Cl-and SO2-4into0~5cm soil, especially F most obviously; while SF could inhibit the accumulation of Cl-and SO2-4into soil surface. SF could reduce Cl-and SO2-4content in topsoil, and increased it in the lowerlayer. It was mainly because that double water retention role of SF made Cl-and SO2-4leached intothe lower soil.(9) With the development stages of sunflower, the Ca2+and Mg2+content with mulch meansin0~120cm decreased. F has accelerated the loss of Ca2+and Mg2+in topsoil (0~40cm), while Sand SF could inhibit their loss. It was because that SF decreased the pH value, and inhibitedsolubility of fixed state calcium and magnesium reducing of the stationary state of calcium andmagnesium. It was the result of plant root respiration, root exudates, and decomposition of crushedwheat straw and the crop root after harvesting. SF slowly declined Ca2+content in30~60cm fromseedling to blossom, and quickly increased it from blossom to harvest. However, F decreasedquickly, and increased slowly. The K+content in0~120cm soil profile of sunflower field was lessin particular. K+accumulated in0~10cm soil, especially in0~5cm soil with S and SF. Insunflower seedling, the Na+content obviously accumulated in0~5cm with N, S and F, especiallywith F. While, SF could inhibit the Na+accumulate into the soil surface. At the same time, Na+content with SF in40~60cm soil increased significantly, because Na+with SF in the surface andcultivated soil was leached down. During blossom and harvest period, the Na+content at60~120cm soil increased significantly, because of more obviously leaching effect with SF. Fromthe point of soil depth, the SAR in0~30cm soil was smaller, that in30~60cm soil was maximum,and that in60~120cm soil was between0~30cm and30~60cm. On the one hand, this is becausethat Na+was leached into the lower layer, at the same time, the Na+content increased in the lowerlayer. On the other hand, it is the result that Ca2+and Mg2+content decreased in the lower layer.The SAR in the soil surface and cultivated soil with SF was significantly lower than othertreatments.This is because that the ratio of soluble Na+in0~5cm soil with SF decreased, while theratio of soluble Ca2+and Mg2+increased. However, soil SAR with SF in30~120cm increased, which explained that ratio of soluble Na+in the lower soil increased, while ratio of Ca2+and Mg2+decreased accordingly. Thus, it can be seen that SF would make the cationic composition changedin the profile. Salt ions beneficial to crops accumulated, those harmful to crops were leached. Thiswould play a certain positive role of improving the soil environment, preventing soil salinization,and curing irrigation area desertification in the northwest arid area, China.更多还原