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1. chinaXiv:202206.00117 [pdf]

湿地土壤气体排放对水位变化响应的持续性动态特征

吕海波
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science

为探索湿地水位变化与土壤气体排放之间的关系,对黄河中游芦苇湿地进行了半注水和满注水样地处理后的动态监测,对比了7 d水位变化过程中土壤气体排放差异。结果表明:注水造成了土壤CO2排放速率的显著差异;随土壤温度上升,H2O、CO2、H2S排放速率都有上升趋势(满注水样地的H2O除外);半注水和满注水造成的影响,H2O排放速率表现为趋同-异步-消失的特征,在注水前期(63.73 h)半注水和满注水差异基本一致,后期差异较大,直至125.64 h后注水的影响才消失,总体分别造成H2O排放总量76.3%和31.3%的增加;CO2排放速率表现为异步-趋同的特征,注水初期环境的改变造成CO2排放的一致减少,37.69~68.66 h二者出现明显差异,68.66~125.64 h水位虽然恢复,但差异仍然存在,注水分别造成CO2排放总量50.1%和43.2%的减少;H2S排放速率表现为无变化-异步-无变化的特征,总体造成H2S排放总量42.3%和32.3%的增加。研究追踪了水位上升后土壤H2O、CO2和H2S排放速率变化的动态过程,其影响具有异步性和持续性的特点,CO2排放速率表现出较长的响应周期。研究结果对于河流湿地生态功能研究具有重要意义,湿地土壤气体排放对水位变化的响应滞后意味着对湿地生态功能的重要影响,其波动过程需要更长时段的精准研究。

submitted time 2022-06-08 Cooperative journals:《干旱区地理》 Hits865Downloads168 Comment 0

2. chinaXiv:202206.00039 [pdf]

南疆盆地亏缺灌溉和覆膜对油莎豆 生物量及产量的影响

丁雅; 杨建明; 李利; 张志浩; 曾凡江
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Other Disciplines of Agriculture, Forestry,Livestock & Aquatic Products Science

研究南疆盆地油莎豆(Cyperus esculentus)滴灌覆膜的效果和最适宜的灌溉制度,为构建南疆盆地油莎豆节水高产管理栽培模式提供参考。通过1 a的试验,在覆膜(M)和不覆膜(NM)条件下,设置3种水分处理水平,即:CK 处理(对照,以当地常用灌溉量 5316.45 m3 ·hm-2 )、T1 处理(灌溉量为 3431.40 m3 ·hm-2)和 T2 处理(灌溉量为4133.85 m3·hm-2 ),灌溉频率为6~10 d,研究覆膜和水分控制对油莎豆生长、品质、产量和水分利用效率的影响。结果表明:(1)油莎豆的密度受水处理的影响显著(P0.05),而根冠比受水处理影响不显著(P0.05)。(2)覆膜处理的草粗脂肪、可溶性淀粉、可溶性糖含量比未覆膜平均提高58.82%3.35%17.20%,覆膜处理块茎的粗脂肪含量、可溶性淀粉、可溶性糖含量均高于未覆膜的,分别增加了7.48%2.56%2.55%,且水处理间差异不显著(P0.05),但是均在T2处理达到最大。(3)产量和水分利用效率随灌溉量增加呈先增加后降低的趋势,其中覆膜条件下,
T2理的草和块茎的产量最大,分别为 3974.55 kg·hm-25253.85 kg·hm-2,较 CK 处理分别显著增加 6.45%36.95%P0.05),较未覆膜条件下,
T2CK平均产量显著增加29.41%34.76%P0.05),水分利用效率也在T2处理达到最大值,其中覆膜处理下,草和块茎在T2处理的水分利用效率较CK显著提高38.63%34.33%P0.05);与T2(覆膜)处理相比,未覆膜条件下CKT2处理的草和块茎的水分利用效率分别显著提高38.91%34.33%P0.05),覆膜处理对草的水分利用效率差异不显著(P0.05),但是对块茎的水分利用效率差异显著(P0.05)。因此,在覆膜条件下,灌溉定额为133.85 m3· hm-2T2)时,不仅提高了油莎豆的品质和产量,也提高了水分利用效率,节约水资源。

submitted time 2022-06-02 Cooperative journals:《干旱区研究》 Hits726Downloads242 Comment 0

3. chinaXiv:202206.00041 [pdf]

氮肥后移对花铃期水分亏缺棉花产量的补偿效应研究

代健敏; 何庆雨; 谢玲; 窦巧巧; 张巨松
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Other Disciplines of Agriculture, Forestry,Livestock & Aquatic Products Science

花铃期是棉花产量形成最关键的时期,为探究氮肥后移对花铃期水分亏缺棉花产量的补偿效应,以新路45号为供试材料,采用裂区试验设计,主区设定2个花铃期滴灌量:常规灌溉量2410 m3·hm-2 W1)为对照、亏缺灌溉量1668 m3·hm-2 W2);副区为3种花铃期施肥比例:N1(花期肥:铃期肥为33)、N2(花期肥:铃期肥为24)、N3(花期肥:铃期肥为42)进行探究。结果表明:(1)相同氮肥条件下,水分亏缺较正常灌溉处理的叶面积指数(LAI)、净光合速率(Pn)显著降低;(2)根据干物质积累Logistic模型,干物质最大积累速率(Vm)出现时间、干物质进入快速积累期时间拐点(t1)均有所提前、干物质快速积累持续时间(?t)有所延长,生殖器官干物质积累量及占比显著降低;(3)水分亏缺处理的单株铃数、单铃重较正常灌溉平均降低了11.7%45.6%,籽棉产量平均降低了17.3%,耗水量、氮肥偏生产力平均降低了35.49%15.97%,水分利用效率平均增加了16.77%。与正常灌溉相比,花铃期水分亏缺条件下,氮肥后移(N2)较N1N3处理的棉花LAIPn都有所增加,且表现为:N2>N1>N3;(4)氮肥后移(N2)处理下的干物质累积量、?tVm表现最优,干物质快速积累期特征值(GT)最为协调,棉花营养生长向生殖生长的转移率最高,为68.25%;(5)与N1N3处理相比,氮肥后移(N2)处理的棉花单株铃数、单铃重分别增加了10.40%16.02%8.41%11.61%,籽棉产量分别增加了7.32%13.88%,耗水量、水分利用效率、氮肥偏生产力均表现为:N2N1>N3。综上所述,氮肥后移通过提高棉花花期LAIPn、减缓盛铃后期的LAIPn的下降幅度,增加地上部分干物质积累量并提高了生殖器官所占比例,调控产量及其构成要素,以减轻水分胁迫对产量的影响。

submitted time 2022-06-02 Cooperative journals:《干旱区研究》 Hits782Downloads264 Comment 0

4. chinaXiv:202205.00163 [pdf]

科技革命、颠覆性技术与智慧农业

胡瑞法; 刘万嘉文
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture

本文首先阐述了科技革命的概念与满足条件,提出并分析了内生及外生农业颠覆性技术及其差异,特别是提出了跨界技术的概念并论证了其对农业科技进步的外生影响。然后分析了作为跨界技术的集大成者——智慧农业技术的特点,智慧农业对传统农业生产技术与生产方式的替代以及智慧农业与农村经济转型的关系。在此基础上讨论了中国智慧农业发展所面临的问题。最后有针对性地提出了促进颠覆性技术创新和智慧农业发展的政策建议,包括加强关键颠覆性核心技术研发、改革现有的农业高等教育体系、推动跨界技术的农业产业化研发以及在高标准农田及规模化养殖场实施智慧农业生产等。

submitted time 2022-05-23 Cooperative journals:《智慧农业(中英文)》 Hits887Downloads254 Comment 0

5. chinaXiv:202205.00116 [pdf]

基于通径分析的低营养水体环境中芽孢杆菌生长与氮转化影响因素研究

黄海洪; 李朝云; 类延菊; 邹万生; 杨品红; 武孟祥
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Fisheries

[目的] 芽孢杆菌在养殖水体等低营养水环境中氮的转化治理方面具有较高的应用价值,但受很多因素的影响,其中又数菌株特性和环境条件较为重要,然而目前对这两种因素的综合研究尚少,基于通径分析的低营养水体环境中芽孢杆菌生长与氮转化影响因素进行分析研究。

[方法] 为此,选取2株芽孢杆菌NT9和YB3作为研究对象,通过平板法测定其水解酶活性和抑菌活性等特性,然后模拟配置了4种低营养水体环境,并应用通径分析方法研究菌株特性和环境条件对芽孢杆菌生长和氮转化作用的影响,如直接效应、间接效应和综合效应等。

[结果] 结果显示,菌株NT9为枯草芽孢杆菌(Bacullis subtilis),与蜡样芽孢杆菌(B. cereus)YB3不同,具有较强的蛋白酶、淀粉酶活性以及抑菌活性,而纤维素酶活性较弱。同时又与菌株YB3相似,在低营养条件下菌株NT9也仅具有有机氮和氨氮降解作用,其中氨氮降解率可达89.3%。通径分析显示,模型的决定系数为0.55-0.95,其它主要的适配度指标也均符合判定标准。菌株的纤维素酶活性(cel)对大多数环境中菌株的生长(gro)以及有机氮、氨氮的降解(dtan)均具有显著的直接促进效应(P<0.001)。水体起始的菌量(iod)、有机氮含量(ion)、氨氮含量(itann)以及时间阶段(stage)等环境因素对grodtan也具有显著的直接影响(P<0.05),但仅限于某些特定的环境。菌株活性与环境因素之间也具有交互作用(P<0.05),对grodtan产生间接效应,增强或抵消直接效应,使某些因素表现出显著的总效应(P<0.05),但也导致其它因素的总效应不显著(P>0.05)。grodtan在某些环境中相互之间也具有直接的促进效应(P<0.001),并且也相互间接影响。研究表明,菌株特性和环境因素的综合作用对低营养水体中芽孢杆菌的生长和氮转化作用具有重要影响,但是在不同的环境中作用的方式不同。

[结论] 因此,在实际应用中,可能需要结合菌株特性和环境条件拟定具体方案,如菌株、氮源的投加量和投加方式等,以达到更好的使用效果。

submitted time 2022-05-18 Hits734Downloads257 Comment 0

6. chinaXiv:202205.00115 [pdf]

淡化条件下生物絮团技术对凡纳滨对虾生长与水质的影响

黄海洪; 李朝云; 类延菊; 邹万生; 杨品红; 武孟祥
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Fisheries

[目的]为研究淡化条件下生物絮团技术对凡纳滨对虾成虾养殖的影响。

[方法]在5‰盐度条件下,应用200L水体进行普通养殖(对照组)与生物絮团养殖(BFT组),放养密度90尾/m3,并测定两种养殖方式对虾生长指标与水质指标,以及分析养殖经济效益和污染物减排效果。

[结果]结果显示,经过63d的养殖,BFT组对虾成活率(100%)和生产力(1.32 kg/m3)显著高于对照组(P<0.05),同时的对虾平均体重(13.20±1.64 g)、特定生长速率(4.26±0.20%/d)和饵料系数(1.09±0.14)等也均优于对照(P>0.05)。

[结论]研究表明,淡化条件下采用BFT养殖凡纳滨对虾能够保持良好的水质,提高成活率,促进生长,降低饵料系数。

submitted time 2022-05-18 Hits919Downloads266 Comment 0

7. chinaXiv:202205.00108 [pdf]

芽孢杆菌特性对养殖水体氮转化作用的影响

黄海洪; 李朝云; 类延菊; 邹万生; 杨品红; 武孟祥
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Fisheries

[目的]研究养殖条件下菌株特性及水体环境对芽孢杆菌氮转化作用的影响。

[方法] 测定了2株芽孢杆菌NT9和YB3的水解酶活性、抑菌活性和生长能力等特性,并对模拟养殖过程中的氮转化作用进行了通径分析。

[结果] 结果显示,菌株NT9属于枯草芽孢杆菌(Bacullis subtilis),在低营养条件下也具有氨氮转化功能,去除率达89.3%,与菌株YB3相比,具有较强的蛋白酶、淀粉酶活性以及抑菌活性,但是生长能力较差。在模拟养殖水体中,2株菌对硝酸氮、亚硝酸氮、溶解氧、pH、碱度等水质条件影响不大,均能够促进有机氮降解,但氨氮转化效果较差,导致水体氨氮显著积累(P< 0.05)。通径分析显示,水体总菌量(cfu)是促进有机氮降解的主要因素,通径系数(直接作用)0.550(P< 0.01),菌株的纤维素酶活性(cel)和生长能力(gro)等都通过cfu对有机氮降解产生较大的间接作用;而微生物的生长增殖活动(总菌增量,dcfu)则是促进氨氮转化的主要因素,通径系数为-0.112(P< 0.01)。

[结论] 研究表明,2株芽孢杆菌在养殖条件下均能够促进饲料蛋白的降解,但是氨氮转化效果不明显,根据通径分析结果,可以通过促进芽孢杆菌生长,对同步转化氨氮进行研究。

submitted time 2022-05-17 Hits892Downloads290 Comment 0

8. chinaXiv:202205.00022 [pdf]

Effects of mixed-based biochar on water infiltration and evaporation in aeolian sand soil

ZOU Yiping; ZHANG Shuyue; SHI Ziyue; ZHOU Huixin; ZHENG Haowei; HU Jiahui; MEI Jing; BAI Lu; JIA Jianli
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science

Abstract: Aeolian sandy soil in mining areas exhibits intense evaporation and poor water retention capacity. This study was designed to find a suitable biochar application method to improve soil water infiltration and minimize soil water evaporation for aeolian sand soil. Using the indoor soil column method, we studied the effects of three application patterns (A (0–20 cm was a mixed sample of mixed-based biochar and soil), B (0–10 cm was a mixed sample of mixed-based biochar and soil and 10–20 cm was soil), and C (0–10 cm was soil and 10–20 cm was a mixed sample of mixed-based biochar and soil)), four application amounts (0% (control, CK), 1%, 2%, and 4% of mixed-based biochar in dry soil), and two particle sizes (0.05–0.25 mm (S1) and <0.05 mm (S2)) of mixed-based biochar on water infiltration and evaporation of aeolian sandy soil. We separately used five infiltration models (the Philip, Kostiakov, Horton, USDA-NRCS (United States Department of Agriculture-Natural Resources Conservation Service), and Kostiakov-Lewis models) to fit cumulative infiltration and time. Compared with CK, the application of mixed-based biochar significantly reduced cumulative soil water infiltration. Under application patterns A, B, and C, the higher the application amount and the finer the particle size were, the lower the migration speed of the wetting front. With the same application amount, cumulative soil water infiltration under application pattern A was the lowest. Taking infiltration for 10 min as an example, the reductions of cumulative soil water infiltration under the treatments of A2%(S2), A4%(S1), A4%(S2), A1%(S1), C2%(S1), and B1%(S1) were higher than 30%, which met the requirements of loess soil hydraulic parameters suitable for plant growth. The five infiltration models well fitted the effects of the treatments of application pattern C and S1 particle size (R2>0.980), but the R2 values of the Horton model exceeded 0.990 for all treatments (except for the treatment B2%(S2)). Compared with CK, all other treatments reduced cumulative soil water infiltration, except for B4%(S2). With the same application amount, cumulative soil water evaporation difference between application patterns A and B was small. Treatments of application pattern C and S1 particle size caused a larger reduction in cumulative soil water evaporation. The reductions in cumulative soil water evaporation under the treatments of C4%(S1), C4%(S2), C2%(S1), and C2%(S2) were over 15.00%. Therefore, applying 2% of mixed-based biochar with S1 particle size to the underlying layer (10–20 cm) could improve soil water infiltration while minimizing soil water evaporation. Moreover, application pattern was the main factor affecting soil water infiltration and evaporation. Further, there were interactions among the three influencing factors in the infiltration process (application amount×particle size with the most important interaction), while there were no interactions among them in the evaporation process. The results of this study could contribute to the rational application of mixed-based biochar in aeolian sandy soil and the resource utilization of urban and agricultural wastes in mining areas.

submitted time 2022-05-09 Cooperative journals:《Journal of Arid Land》 Hits699Downloads197 Comment 0

9. chinaXiv:202205.00023 [pdf]

Impact of rainfed and irrigated agriculture systems on soil carbon stock under different climate scenarios in the semi-arid region of Brazil

André L CARVALHO; Renato A ARA?JO-NETO; Guilherme B LYRA; Carlos E P CERRI; Stoécio M F MAIA
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture

Abstract: Understanding the dynamics of soil organic carbon (SOC) is of fundamental importance in land use and management, whether in the current researches or in future scenarios of agriculture systems considering climate change. In order to evaluate SOC stock of the three districts (Delmiro Gouveia, Pariconha, and Inhapi districts) in the semi-arid region of Brazil in rainfed and irrigated agriculture systems under different climate scenarios using the Century model, we obtained RCP4.5 and RCP8.5 climate scenarios derived from the Eta Regional Climate Model (Eta-HadGEM2-ES and Eta-MIROC5) from the National Institute for Space Research, and then input the data of bulk density, pH, soil texture, maximum temperature, minimum temperature, and rainfall into the soil and climate files of the Century model. The results of this study showed that the Eta-HadGEM2-ES model was effective in estimating air temperature in the future period. In rainfed agriculture system, SOC stock under the baseline scenario was lower than that under RCP4.5 and RCP8.5 climate scenarios, while in irrigated agriculture system, SOC stock in the almost all climate scenarios (RCP4.5 and RCP8.5) and models (Eta-HadGEM2-ES and Eta-MIROC5) will increase by 2100. The results of this study will help producers in the semi-arid region of Brazil adopt specific agriculture systems aimed at mitigating greenhouse gas emissions.

submitted time 2022-05-09 Cooperative journals:《Journal of Arid Land》 Hits419Downloads196 Comment 0

10. chinaXiv:202205.00037 [pdf]

Soil carbon mineralization as affected by water content and nitrogen rate after ryegrass incorporated into soil

Meijuan Lu; Jiancheng Xu; Xiaowei Wang; Wenting Yang
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Agronomy

Planting cover crop has been suggested as a way of increasing soil organic carbon in agricultural land. Ryegrass (Lolium multiflorum L.), as a cover crop, could improve soil fertility and lower soil CO2 emission. However, effects of soil water content and nitrogen on soil carbon mineralization after ryegrass incorporation are not fully understood. The present study was to investigate the effect of soil water content and nitrogen rate on soil carbon mineralization after ryegrass incorporated into upland red soil (Ferralsols). A laboratory experiment was established, including soil water contents [15% (W1), 30% (W2), 45% (W3)] and nitrogen rates [0 (N1), 60 mg/kg(N2), 120 mg/kg(N3)]. The results showed that the highest soil carbon mineralization accumulation was observed in W3N3. Nitrogen application inhibited carbon mineralization rate and accumulation in the late stage of ryegrass incorporation at W1, but increased carbon mineralization rate and accumulation at W2. With increasing soil water content, nitrogen application could improve soil carbon mineralization at the early stage of ryegrass incorporation. In conclusion, soil nitrogen and water content could regulate soil carbon mineralization. Considering to reduce the soil CO2 emissions, rational nitrogen application should be taken seriously during cover crop (ryegrass) incorporated into the upland red soil.

submitted time 2022-05-08 Hits401Downloads216 Comment 0

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