山西省灌溉农田的土壤培肥问题

干旱缺水地区灌溉施肥,不仅是为了供给当季作物所需,而且应成为培肥土壤,发展持续农业的重要手段,选择有机质,全氮,速效磷含量作为土壤肥力的基础指标,列举了山西省部分灌区土壤肥力状况及不同作物土壤肥力特征,表明灌溉,施肥在土壤培肥中起主导作用,介绍了根据供水条件和土壤碳氮比来选择肥料和施肥方法的一般原则。     

麦秸覆盖旱地棉田少耕培肥效果

１９８８－１９９０年连续３年在河北省黑龙港地区旱地进行了麦秸覆盖少耕研究，结果表明：麦秸覆盖旱地棉田，有调节地温，保持土壤水分，抑制杂草，提高土壤生物活性和培肥地力的良好功能，有明显增产效果，增产量随着麦秸覆盖量而递增，每亩覆盖麦秸４５０公斤＞３００公斤＞１５０公斤，覆盖时期以蕾期产量最高，花期次之，蕾期每亩覆盖麦秸４５０公斤是最佳组合，３年平均比对照增产１１．９％。     

旱地农田土壤培肥技术

土壤是农业生产的基本资料．肥力是土壤的基本特征。在生产实践中,往往是水分和养分等土地因素限制光能的转化和利用。即或是地力较高,如果只用不养或用多养少,土地肥力也会逐渐变低。因此,培肥地力是农业生产中不容忽视的重要环节。     

不同培肥措施对藏东南土壤酶活性的影响

对进行不同培肥措施后土壤进行理化性状和酶活性测定，结果表明：土壤中的脲酶、转化酶、碱性磷酸酶活性与土壤肥力有良好的相关性。不同培肥措施中，以有机肥（厩肥、秸秆）配施化肥对脲酶、转化酶、碱性磷酸酶活性影响最大，分别是单施化肥处理的酶活性的1．47、3．31、1．07倍。各培肥措施中，以有机肥（厩肥、秸秆）配施化肥效果最好，有机无机结合中厩肥＋化肥又优于秸秆＋化肥。建议藏东南地区采用有机无机结合方式培肥土壤。     

不同培肥措施对黔东几类土壤腐殖质的影响

通过5年的定位试验，结果表明，长期有机无机肥配施或粮肥轮作、间种配施化肥均能提高黄壤土类黄泥土、红壤土类黄红泥土和潮土类潮泥土的有机质、腐殖质和活性腐殖质含量，其中胡敏酸、富里酸也相应增加，但以粮肥轮作、间种配施化肥的培肥效果最好。粮肥轮作、间种配施化肥还能提高土壤腐殖质的胡／富比值。各处理的影响不仅仅局限于土壤耕层，但以0～50cm土层的效果显著。     

阜南县土壤养分状况及培肥措施

阜南县地处淮河行蓄洪区，自然灾害频繁，土壤贫瘠，是安徽省贫困县之一。土壤养分分析结果表明，全县绝大部分土壤需增施有机肥和氮、磷化肥；部分土壤还明显缺钾，文章提出了土壤培肥措施，对沿江地区有一定的参考价值。     

培肥措施培肥土壤的效果与机理研究进展

土壤肥力是农业可持续发展的基础资源,培肥是维持农业土壤肥力水平最主要的措施之一,藉以补偿由于养分随农产品收获及农作物废弃物(如秸秆)带出农田对土壤养分库亏损造成的影响。如何对农田土壤进行有效培肥,达到既提高作物产量和品质,又使农田土壤保持较高肥力,同时有效控制农业面源污染,维护农田良好生态环境,已成为目前农业现代化面临的重要课题之一。本文综述了国内外有关培肥措施与土壤肥力水平关系的研究进展,重点阐述了培肥措施与土壤基本理化性状、土壤酶活性、土壤微生物肥力指标、土壤动物肥力指标之间关系的规律,并指出培肥措施与土壤肥力关系方面今后的研究重点,主要包括:有机肥的精细化高效化投入与土壤肥力关系研究、土壤动物学肥力指标的深入研究、土壤长期培肥的土壤生物学过程研究、土壤培肥与农业面源污染问题研究。本文旨在为通过合理培肥措施来提高农田土壤肥力及维护农田良好生态环境方面的深入研究提供科学依据。     

长期不同施肥方式对华北地区温室和农田土壤团聚体形成特征的影响

土壤的团聚状况是土壤重要的物理性质之一,团聚体数量是衡量和评价土壤肥力的重要指标。施用有机肥是提高土壤有机碳(SOC)含量、促进土壤团聚体形成和改善土壤结构的重要措施。本文以华北地区曲周长期定位试验站的温室土壤和农田土壤为研究对象,运用湿筛法,对比研究施用化肥(NP)、有机肥加少量化肥(NPM)、单施有机肥(OM)3种施肥方式对温室和农田两种利用方式土壤水稳性团聚体含量、分布和稳定性的影响,以提示施肥措施对不同土地利用方式土壤水稳性团聚体特征的影响。结果表明:在温室土壤和农田土壤中,OM处理较NP和NPM处理显著降低了土壤容重,增加了土壤有机质含量(P0.05),且在0~10 cm土层中效果最为明显。其中在温室土壤0~10 cm土层,单施有机肥处理(OM1)的土壤容重为1.17 g·cm~(-3),分别较施用化肥(NP1)和有机肥加少量化肥(NPM1)处理降低12.0%和8.6%,OM1的土壤有机质含量为54.81 g·kg~(-1),较NP1和NPM1增加104.8%和35.7%;在农田土壤0~10 cm土层,单施有机肥处理(OM2)的土壤容重为1.19 g·cm~(-3),较施用化肥(NP2)、有机肥加少量化肥(NPM2)分别降低8.5%和7.0%,OM2的土壤有机质为22.67 g·kg~(-1),较NP2、NPM2分别增加23.1%和15.0%。温室土壤和农田土壤中,0~10 cm、10~20 cm和20~40 cm层土壤团聚体的平均重量直径(MWD)和几何平均直径(GMD)均为OMNPMNP;OM处理下水稳性团聚体的分形维数(D)值最低,NP处理下最大。OM处理显著降低0~20 cm土层内水稳性团聚体的D值,表层0~10 cm土层效果最为明显,土壤结构明显得到改善;相比农田土壤,温室土壤稳定性指标变化最为明显,团聚体结构改善效果最好。土壤有机质含量与0.25 mm水稳性团聚体含量间呈极显著正相关关系(P0.001),说明土壤有机质含量越高,0.25 mm水稳性团聚体的含量就越高,土壤团聚体水稳性越强,土壤结构越稳定。因此有机施肥方式能在补充土壤有机碳库和有效养分含量的同时,显著增加土壤中大团聚体的含量及其水稳性,是提高华北平原农田土壤、尤其是温室土壤结构稳定性和实现土壤可持续发展的有效措施。     

Effect of lignite humic acid treatment on the rate of decomposition of wheat straw

Comparisons were made between the rates of microbial respiration during the incubation of milled wheat straw in the presence or absence of a dispersal of lignite humic acids. Lignite treatment significantly reduced both the rate of O₂ consumption and CO₂ evolution from the straw substrate over a 4-week period. In view of this observed inhibitory effect, additions of exogenous humic acids from lignite during composting might have a practical application as a means of increasing the microbial stability of horticultural composts derived from plant waste materials.     

Herbicide effects on soil arthropod dynamics and wheat straw decomposition in a North Carolina no-tillage agroecosystem

Summary Herbicide combinations of paraquat, glyphosate, alachlor, linuron, fluazifopbutyl, aciflurofen, and bentazon were investigated for their impact on soil arthropod population dynamics and surface wheat straw decomposition (weight loss) within a North Carolina coastal plain agroecosystem. Herbicides were applied twice (preemergence and mid-bloom) at recommended field rates to soybeans no-till planted into wheat residue. Separate measurements were made for surface crop residue and soil-dwelling (0–3 cm depth) arthropods. Decomposition of herbicide (glyphosate) and nonherbicide-treated wheat straw residue was compared using mesh bag techniques. Decay rate constants were estimated for glyphosate and nonherbicide-treated wheat straw residue by fitting a two-component model to the data. Comparison of soil microarthropod numbers from herbicide and nonherbicide treatments showed no consistent trend, suggesting that abiotic factors such as soil temperature and moisture were probably more significant than herbicide effects in regulating soil microarthropod number and activity. Herbicides had no effect on soil macroarthropod number or activity until late in the season when macroarthropods were most abundant under weedy, no-tillage conditions. Moist soil and litter, low soil temperature, floral diversity, and high weed-seed availability probably enhanced macroarthropod numbers in nonherbicide treatments. Decomposition (ash-free weight loss) of nonherbicided, surface crop residues was more rapid than herbicide (glyphosate) treated, indicating that herbicide effects occur at the decomposer as well as producer level of agroecosystems.Paper No. 9957 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7601, USA     

少免耕对小麦/玉米农田玉米还田秸秆腐解的影响

为了研究高产灌溉条件下土壤耕作模式对还田玉米秸秆腐解的影响,在山东龙口采用4种土壤耕作模式（常规耕作秸秆还田、旋耕秸秆还田、耙耕秸秆还田、免耕秸秆覆盖）进行了一年两季田间试验,测定了秸秆腐解率、秸秆腐解速率和秸秆的纤维素含量。结果表明：秸秆腐解速率与土壤温度具有显著的相关性。旋耕秸秆还田和耙耕秸秆还田两种少耕模式和常规耕作秸秆还田模式的秸秆腐解率、平均秸秆腐解速率无显著差异,说明少耕模式并不因减少耕作程序而降低作物秸秆在田间的腐解。免耕模式的秸秆腐解率和腐解速度显著低于以上3种耕作模式,经过小麦和玉米两个生长季节后仍有37.78%的玉米秸秆剩余,而且秸秆中纤维素质量分数为20.69%,腐解质量差,会对下年作物的出苗产生 影响。     

小麦玉米秸秆连续还田对土壤有机质红外光谱特征及氮素形态的影响

通过6年的田间定位试验,探讨了CK(不施肥,秸秆不还田)、SF(施肥,秸秆不还田)、T1(施肥,玉米秸秆还田)、T2(施肥,小麦秸秆还田)、T3(施肥,玉米小麦秸秆还田)5种处理对土壤氮素形态和有机质红外光谱特征的影响。结果显示:与SF相比较,T1、T2、T3处理使土壤有机氮含量分别增加3.7%、15.9%和18.5%,土壤无机氮含量分别减少15.5%、15.9%和24.0%,其中铵态氮分别降低11.3%、6.0%和12.0%,土壤硝态氮含量分别降低19.3%、22.9%和32.1%;与SF相比较,T1、T3处理土壤有机质(SOM)的C/N分别降低2.8%和1.4%,T2处理SOM的C/N提高1.4%;C/O分别提高9.2%、12.8%和12.1%;而H/C分别降低4.6%、5.5%和4.6%。红外图谱分析显示,T1、T2、T3处理引起3 500~3 200 cm?1处的吸收峰增加,2 924 cm?1处出现了新的弱峰,表明SOM的脂肪族特征增加,且以1 630 cm?1处为中心的宽带吸收峰强度明显增加,SOM芳构化程度增强。研究表明,施肥显著提高了土壤有机氮、无机氮含量,以及土壤有机质的C/N和C/O。而秸秆还田降低了土壤无机氮,提高了土壤有机氮,使SOM的C/N、H/C下降,C/O上升,同时提高了SOM中酚基、羟基、羧基、芳香碳和酰胺含量,其中以小麦、玉米秸秆双季还田的效果最为显著。     

小麦秸秆浸提液和腐解液对水稻的化感效应

通过设置小麦秸秆浸提液和腐解液对水稻种子发芽和幼苗生长发育影响试验,明确小麦秸秆对水稻的化感效应.水稻种子萌发试验采用平板培养法,水稻生长发育试验采用砂培法.试验结果表明:与对照相比,小麦秸秆浸提液和腐解液均显著降低水稻种子的发芽指数和水稻植株生物量、叶绿素含量以及根系活力(p＜0.05),同时显著增加水稻植株丙二醛含量(p＜0.05);小麦秸秆腐解液对水稻的化感效应强于秸秆浸提液,小麦秸秆叶部浸提液对水稻的化感效应强于茎秆浸提液,小麦秸秆15d腐解液对水稻的化感效应强于7d腐解液;4种浸提液或腐解液5倍稀释后均减缓了对水稻发芽和植株生长发育的抑制作用.小麦秸秆浸提液和腐解液的总酚酸含量均较高,含量介于90.80～222 mg L-1,且总酚酸含量与水稻植株鲜重、根系活力、叶绿素以及水稻发芽指数显著负相关,而与水稻植株丙二醛含量显著正相关.小麦秸秆浸提液和腐解液均对水稻产生化感效应,其作用强度与秸秆腐解方式、秸秆不同部位及腐解时间有关,同时小麦秸秆化感效应的产生与浸提液和腐解液中的酚酸含量有关.     

Bacterial diversity in soils subjected to long-term chemical fertilization can be more stably maintained with the addition of livestock manure than wheat straw

Addition of organic matter such as livestock manures and plant residues is a feasible practice to mitigate soil degradation caused by long-term application of chemical fertilizers, and the mitigation is largely mediated though activities of the soil-dwelling microorganisms. However, the roles of different kinds of organic matter in maintaining bacterial community structure have not been assessed in a comparative manner. In this study, 454 pyrosequencing of 16S rRNA gene was employed to compare the bacterial community structure among soils that had been subjected to 30 years of NPK fertilization under six treatment regimes: non-fertilization control, fertilization only, and fertilization combined with the use of pig manure, cow manure or low- and high-level of wheat straws. Consistent with expectation, long-term application of NPK chemical fertilizers caused a significant decrease of bacterial diversity in terms of species richness (i.e. number of unique operational taxonomic units (OTU)), Faith's index of phylogenetic diversity and Chao 1 index. Incorporation of wheat straw into soil produced little effects on bacterial community, whereas addition of either pig manure or cow manure restored bacterial diversity to levels that are comparable to that of the non-fertilization control. Moreover, bacterial abundance determined by quantitative PCR was positively correlated with the nutritional status of the soil (e.g., nitrate, total nitrogen, total carbon, available phosphorus); however, bacterial diversity was predominantly determined by soil pH. Together, our data implicate the role of livestock manures in preventing the loss of bacterial diversity during long-term chemical fertilization, and highlight pH as the major deterministic factor for soil bacterial community structure.     

砂姜黑土长期施肥对小麦生长的影响研究

砂姜黑土20年长期定位施肥试验研究结果表明,不同施肥处理对小麦产量的影响明显,各处理产量为Ⅳ>Ⅲ>Ⅱ>Ⅰ>CK,单施化肥有利于培育大蘖壮苗,利用增穗增粒对提高产量有一定作用,但因提高土壤肥力作用较小而难以高产。单施有机肥培肥作用明显,但其养分释放缓慢,影响小麦对养分的吸收,且生育前期营养生长不良,群体不足,小麦增产幅度较小。有机肥与化肥配施养分供应平衡,群体动态、产量结构合理,是砂姜黑土地区小麦持续高产和土壤培肥的有效措施,但应同时重视K肥施用。     

麦秆还田氮肥运筹对水稻产量及土壤氮素供应的影响

通过田间对比试验,研究了小麦秸秆全量还田后不同N肥运筹模式对水稻生长及土壤N素供应的影响。结果表明,小麦秸秆全量还田使水稻增产5.3%,且N肥运筹模式由传统模式A(基蘖肥:穗肥=5:5,基肥:分蘖肥=6:4)优化为B(基蘖肥:穗肥=6.5:3.5,基肥:分蘖肥=8:2)时,增产幅度更大,达9.3%。秸秆全量还田主要通过提高水稻结实率和成穗率,增加有效穗数,实现水稻增产。秸秆还田影响了水稻生长进程,表现为抑制水稻前期(孕穗期)生长和N素累积,而促进后期生物量增加和N素累积。同一时期,N肥模式B水稻生物量、N素累积量均高于模式A。秸秆全量还田后,土壤矿质N发生变化,水稻生育前期较不还田处理(CK)低,而后期较CK高,且N肥运筹模式B较A高。秸秆还田提高了N肥利用率,RNA、RNB分别比CK增加4.1和8.6个百分点,且土壤N素表观盈余量表现为:RNBRNACK。因而,小麦秸秆全量还田,并采用N肥运筹模式B,是实现水稻高产,维持土壤N素平衡的有效措施。     

Phosphomonoesterase production and persistence and composition of bacterial communities during plant material decomposition in soils with different pH values

The aim of this work was to study the synthesis and persistence of acid and alkaline phosphomonoesterases in three soils with different pH values amended with ryegrass residues. The organic input increased soil respiration, as estimated by CO₂-C evolution in all soils. The ATP content of the three soils showed a 3-7-fold increase between 7 and 10 d in the different soils since the amendment. The dsDNA content of the three amended soils also peaked between 7 and 10 d, increasing by 2.5-3.5 times in the different soils. The bacterial species richness increased in the amended as compared to the control soils during the early stages (7-10 d) of organic matter decomposition, as indicated by the decreasing values of the Sørensen similarity index between the treatments in this period. Soil amendment increased the alkaline phosphomonoesterase activity by 6, 8 and 15 times in the Vallombrosa acidic, Romola neutral and Vicarello alkaline soil, respectively, whereas the acid phosphomonoesterase activity showed a 6-, 2- and 10-fold increase in the Vallobrosa acidic, Romola neutral and Vicarello alkaline soil, respectively. Phosphatase activities peaked between 4 and 10 d, depending on the activity and the soil considered, but activity of alkaline phosphomonoesterase was higher in alkaline soils and persisted longer than the acid phosphomonoesterase activities; the opposite occurred in the acid soil. During a 180 d decomposition period, both acid and alkaline phosphomonoesterase activities were related to dsDNA and ATP contents in all soils. Peaks of phosphmonoesterase activity coincided with the changes in the composition of the bacterial microflora, as detected by 16S-rDNA analysis, although no relationship between bacterial community composition and persistence of the phosphomonoesterase activities could be shown. It was concluded that acid and alkaline phosphomonoesterases are produced in greater amounts during plant residue decomposition, and that in acid soils acid phosphomonoesterase activity predominates and in neutral and alkaline soils alkaline phosphomonoesterase activity predominates. However, the persistence of newly produced enzymes is determinated by other factors such as soil texture, organic matter content and formation of soil colloid-enzyme complexes.