【作者】 王芳；

【导师】 同延安；

【作者基本信息】 西北农林科技大学 ， 植物营养学， 2010， 硕士

【摘要】 为研究施用不同有机料对渭北旱塬土壤养分变化和肥力演变的影响,寻求合理的土壤培肥措施,2007至2009年在西北农林科技大学甘井旱农试验基地布置了田间定位试验,种植作物冬小麦,共设7个处理:1)不施肥(CK);2)施用化肥(T1);3)化肥+低量秸秆(玉米茎叶3750 kg·hm-2,干质量,下同,T2);4)化肥+中量秸秆(玉米茎叶7500 kg·hm-2,T3);5)化肥+高量秸秆(玉米茎叶15000 kg·hm-2,T4);6)化肥+秸秆堆肥(7500 kg·hm-2,T5);7)化肥+厩肥(15000 kg·hm-2,T6),并于小麦收获期采集耕层(0~20 cm)土壤样品,系统研究了不同有机物料对土壤团聚体特征、土壤养分平衡、作物产量、土壤理化性质和微生物学特性的影响,对其短期培肥效应进行了评价,并结合试验对渭北旱塬大田作物施肥和种植管理等情况进行了综合调查,取得的主要结果如下:1、通过田间试验和室内分析,研究了施用不同有机物料对渭北旱塬耕地土壤化学性质和酶活性的影响,选取有机质等10个能够反映土壤肥力质量特性的定量因子作为评价指标,采用因子分析对土壤肥力质量进行综合评分,然后用欧氏距离最短距离法对其进行聚类,最后利用作物产量结果进行验证。结果表明:通过土壤有机培肥,土壤肥力质量和作物产量均有显著提高,与单施化肥相比,施加秸秆堆肥和厩肥处理的小麦产量分别提高了20.43%和22.38%;对土壤肥力综合进行评价,秸秆堆肥配施化肥的土壤肥力质量最高,综合得分达56.53,厩肥配施化肥较高,高量秸秆配施化肥次之。可见,通过秸秆堆肥或厩肥配施化肥进行培肥土壤,能显著提高土壤肥力水平,从而提高作物产量;利用有机质等10项土壤肥力特性因子,采用因子分析对土壤肥力质量进行综合评价,能够准确反映土壤肥力水平,预测土壤生产力状况。2、通过田间试验和室内分析,研究了施用不同有机物料对渭北旱塬耕地土壤理化性质的影响。从物理性质变化来看,与单施化肥处理T2相比,有机培肥处理的土壤容重总体呈现出缓慢下降的趋势,其中秸秆堆肥与厩肥处理效果较明显,且厩肥处理下降幅度达到了显著水平,达6.56%。T3、T5和T6处理与单施化肥处理T2相比,降低了>10 mm的风干团聚体含量,其中T3达到显著水平,降低了40.35%。除T4处理外,其他4个有机培肥处理均提高了5~3 mm团聚体含量,同样是T3处理使其显著增加。有机培肥处理从不同程度上增加了>5 mm、5~2 mm和2~0.25 mm的水稳性团聚体含量,T5显著增加了>5 mm的团聚体的含量,为6.49%;T4显著增加了5~2 mm的团聚体含量,达到77.98%;T6处理则明显增加了2~0.25 mm的团聚体含量。经土壤有机培肥后,土壤团聚体MWD、GMD均有所变化,干筛法下,各处理的团聚体MWD、GMD表现出T5>T4>T1>CK>T3>T6>T2的趋势。湿筛法下,有机培肥T3-T6处理的团聚体MWD、GMD均比单施化肥处理T1高,说明土壤培肥措施在改善土壤结构状况方面产生了正面的效果。从化学性质变化来看,与单施化肥处理T2相比,不同有机培肥处理的土壤有机质并没有明显的增加或下降,全氮含量在有机培肥后有所增加,但差异并不显著,同时全磷和全钾也有类似趋势。土壤速效养分均有整体增加的趋势,但是差异并不显著,与土壤全量养分变化趋势相似。土壤阳离子交换量均有所增加,且都达到了差异显著水平。pH值没有发生明显的变化,总体维持在8.32左右,但高量秸秆配施化肥处理与单施化肥处理比,pH下降明显。所有处理下小麦产量由高到低的顺序依次为T5>T6>T4>T2>T3>T1>CK。其中单施化肥处理T1较对照有显著提高,提高幅度为28.05%,有机培肥处理T2-T6与T1相比均有不同程度的提高,提高幅度在5.72%~12.58%之间,但均未达到显著水平。本试验中主要肥力因素相互之间或与小麦产量之间均存在极显著或显著的正相关关系,与有机质、pH等因素间未显示出相关关系。3、通过田间试验和室内分析,研究了施用不同有机物料对渭北旱塬耕地土壤微生物学特性(土壤微生物量、土壤酶活性)及土壤肥力的影响。结果表明:不同有机培肥处理下土壤中SMBC变化介于156.84～452.95 mg·kg-1之间,SMBN变化介于16.57～47.68 mg·kg-1之间;单施化肥(NPK)与不施肥的CK相比,SMBC、SMBN、微生物商(qMB)、微生物量碳/氮比(SMBC/SMBN)、脲酶、碱性磷酸酶、蔗糖酶活性以及土壤有机质(SOM)、全氮(STN)、全磷(STP)、CEC含量都有所提高;化肥与秸秆堆肥、厩肥或不同量秸秆配合施用,土壤微生物学特性(SMBC、SMBN、qMB、脲酶、碱性磷酸酶、蔗糖酶活性)以及部分土壤养分状况(STN、CEC、AP、AK)比单施NPK处理得到进一步改善,其中化肥配施秸秆堆肥处理效果最明显。同时,SMBC与AN、AP、AK的含量均呈极显著正相关,与STN、STP呈显著正相关;SMBN与AP呈极显著正相关,与STP、AN、AK呈显著相关;SMBC和SMBN又均与CEC呈显著正相关关系;qMB与AN、AP、AK含量呈极显著正相关,与STN、STP、CEC含量呈显著正相关;脲酶、碱性磷酸酶与STN、CEC、AN、AK含量均呈极显著正相关,与STK、AP呈显著正相关;蔗糖酶与土壤养分含量之间没有明显的相关性。4、2008年对陕西省渭北旱塬2个县的200多位农户近年来冬小麦、春玉米2种主要大田作物的产量、肥料施用量及其它管理措施进行了现状调查。结果表明,冬小麦的化肥纯N平均用量为154.9 kg·hm-2,P2O5平均用量为87.7 kg·hm-2,K2O平均用量为31.7 kg·hm-2;春玉米的化肥纯N平均用量为148.6 kg·hm-2,P2O5平均用量为79.5 kg·hm-2,K2O平均用量为16.0 kg·hm-2。冬小麦的产量和施肥量在农户间的差别较大,产量较低,45.6%的农户施用氮肥过量,施用有机肥的农户占调查总数的比例较小,仅占4.8%。春玉米表现出施肥不足的现象,并且产量同样较低,平均亩产272 kg。农户施用的肥料品种单一,施肥方式和施肥时期不尽合理。为此提出陕西省旱地大田作物应增施有机肥,并注意合理施肥和科学管理相结合的建议。更多还原

【Abstract】 A two-year field experiment was conducted in Weibei rainfed highland of Shaanxi Province to evaluate the effects of different organic materials application on soil fertility characteristics and winter wheat yield. The experiment consisted of seven treatments: no fertilizer(CK), mineral fertilizers(T1), mineral fertilizers plus low amounts of maize straw(T2), mineral fertilizers plus medium amounts of maize straw(T3), mineral fertilizers plus high amounts of maize straw(T4), mineral fertilizers plus straw compost(T5), mineral fertilizers plus manure(T6). At the same time, a fertilizer application investigation combined with experiment was carried out to investigate the fertilization status of households in dryland area within Weibei rainfed area. The main results are as follows:1、A comprehensive evaluation was made on the effects of applying different organic materials on the soil chemical properties and enzyme activities in Weibei rainfed highland, based on field experiment and laboratory analysis. A total of ten quantitative indices were selected, and factor analysis and minimum Euclidean distance method were employed to evaluate the overall soil fertility. Crop yield was used to verify the evaluation results. Applying organic materials promoted soil fertility and crop yield significantly. Compared with applying chemical fertilizer alone, its combination with straw compost and with organic manure increased the wheat yield by 20.43% and 22.38%, respectively. The soil quality under the combined application of chemical fertilizer with straw compost was the highest, with an integrated score up to 56.53, followed by the combined application of chemical fertilizer with organic manure, and of chemical fertilizer with high amount straw. Therefore, a combined application of chemical fertilizer with straw compost or organic manure could improve the soil fertility significantly, and thereby, increase the crop yield. Using the selected 10 factors and factor analysis to evaluate the quality of soil fertility could accurately reflect the soil fertility level, and predict the soil productivity in the highland.2、The effect of different organic materials application on soil physical and chemical characteristics was studied through field experiments and laboratory analysis. Compared with T2 treatment, in terms of soil physical properties, soil bulk density under other organic fertilization treatments declined slightly, and it obtained the highest decrease (by 6.56%) in treatment with fertilizers input manure. The air-dried aggregate (>10 mm) content under T3、T5 and T6 treatment decreased compared to T2 treatment, and T3 treatment with the amplitude decrease(40.35%). In addition to T4 treatment, 5~3 mm aggregate content increased under the other four organic manure treatments, especially in T3 treatment. The >5 mm, 5~2 mm and 2~0.25 mm water-stable aggregate content increased from different levels under the organic fertilization treatments. It is increased to 6.49% under T5 treatment for >5 mm aggregate content; 5~2 mm aggregate content significantly increased by 77.98% and 2~0.25 mm aggregate content increased obviously under T6 treatment. Mean weight diameter (MWD) and geometric mean diameter (GMD) of dry-aggregates showed the following trend: T5>T4>T1> CK>T3>T6>T2, while the wet sieving results showed that the MWD and GMD under T3-T6 treatments were higher than T1 treatment. In terms of soil chemical properties, there were no significant differences with the organic matter content under T3-T6 treatments than T1 treatment. The total and available nutrient content showed the general increase. The soil cation exchange capacity increased significantly under each organic fertilization treatment compared to T1 treatment. There was no obvious influence on soil pH with each treatment except T4 treatment. Compared with T1 treatment, soil pH decreased distinctly under T4 treatment. The wheat yield under all treatments followed the order T5>T6>T4>T2>T3>T1>CK. The yield under T1 treatment was significantly higher than no fertilization treatment by 28.05%. T2-T6 treatments increased the yield significantly in the range of 5.72% to 12.58% compared with T1 treatment. There was obvious correlation between the soil nutrients and wheat yield, but soil organic matter and pH were not correlated with soil nutrients and wheat yield.3、The effect of different organic materials applied on soil microbiological properties such as soil microbial biomass and soil fertility was studied in Weibei rainfed highland soils through field experiments and laboratory analysis. The result showed that in different organic materials application treatments, the contents of SMBC changed between 156.84 mg·kg-1 to 452.95 mg·kg-1, and the contents of SMBN changed from 16.57 mg·kg-1 to 47.68 mg·kg-1. Compared with CK, T1 treatment increased soil microbial biomass C (SMBC) & N (SMBN), qMB, SMBC/SMBN, urease activity, invertase activity, alkaline phosphatase, soil organic matter(SOM), soil total nitrogen(STN), soil total phosphorus(STP) and CEC. The other organic materials fertilization treatments improved some soil microbial properties(SMBC & SMBN, qMB, urease activity, alkaline phosphatase, invertase activity) and increased some soil nutrients contents(STN、CEC、Available phosphorus、Available potassium) compared with T1 treatment. All these properties in the treatment of fertilizers with straw compost were the highest level. Meanwhile, some of soil microbial properties (SMBC, SMBN, urease activity and alkaline phosphatase) were positively correlated with soil nutrients. qMB was significantly correlated with STN, STP and CEC contents. The correlation between invertase activity and soil nutrients was not obvious.4、The crop yield、fertilizer application rate and other management measures in Heyang and Fuping in Weibei area were investigated in 2008. The main results showed that average N rate in winter wheat and spring maize was 154.9 and 148.6 kg·hm-2, the average P2O5 rate in winter wheat and spring maize was 87.7 and 31.7 kg·hm-2 and K2O rate in winter wheat and spring maize was 31.7 and 16.7 kg·hm-2 respectively. There existed big difference for wheat yield and fertilizer amount with different farmers. 45.6% of farmers applied excessive nitrogen, while only 4.8% of farmers applied organic manure. Fertilizer input on spring maize was not enough and the yield was low, average yield of maize was 272 kilograms per mu. The fertilizer species was single, the local farmers’fertilization habit and period were unreasonable. According to these situations, we will recommend reasonable fertilization method and suggest the departments help the farmers to know fertilization technology.更多还原