可持续农业及其指示因子研究进展

回顾了可持续农业的演变和发展历史,概括介绍了可持续农业的定义,内涵,理论基础以及研究方法和内容。重点评述了国外关于可持续农业量化研究进展情况,对几个公认的量化生态可持续性的指示因子：土壤,水分,生物多样性等进行了仔细分析,以期对国内农业的可持续发展研究有所借鉴和启发。文章最后还结合我国目前农业发展中存在的问题以及未来农业面临的挑战,指出：提高农产品的数量和质量,防止水土流失和荒漠化,提高水分利用率以及生物多样性保护是我国农业可持续发展的关键指示因子,并提出了21世纪我国可持续农业发展的几个模式。     

Assessment of Nutrient Leaching Losses and Crop Uptake with Organic Fertilization,Water Saving Practices and Reduced Inorganic Fertilizer

The increasing world population has forced excessive chemical fertilizer and irrigation to complete the global food demand, deteriorating the water quality and nutrient losses. Short-term studies do not compile the evidences; therefore, the study aimed to identify the effectiveness of reduced doses of inorganic fertilizer and water-saving practices, hence, a six-year experiment (2015–2020) was conducted in China to address the knowledge gap. The experimental treatments were: farmer accustomed fertilization used as control (525:180:30 kg NPK ha⁻¹), fertilizer decrement (450:150:15 kg NPK ha⁻¹), fertilizer decrement + water-saving irrigation (450:150:15 kg NPK ha⁻¹), application of organic and inorganic fertilizer + water-saving irrigation (375:120:0 kg NPK ha⁻¹ + 4.5 tones organic fertilizer ha⁻¹), and application of controlled-release fertilizer (80:120:15 kg NPK ha⁻¹). Each treatment was replicated thrice following a randomized complete block design. The results achieved herein showed that control has the highest losses in the six-year study for total nitrogen (225.97 mg L⁻¹), total soluble nitrogen (121.58 mg L⁻¹), nitrate nitrogen (0.93 mg L⁻¹), total phosphorus (0.57 mg L⁻¹), and total soluble phosphorus (0.57 mg L⁻¹) respectively. Reduced fertilizer and water application improved crop nutrient uptake, nitrogen concentration was significantly enhanced with organic and inorganic fertilizer + water-saving irrigation, P concentration was increased with fertilizer decrement + water-saving irrigation, and K concentration was improved with fertilizer decrement + water-saving irrigation. Hence, this study concludes that reduced inorganic fertilizer dose combined with water-saving practices is significantly helpful in reducing nutrient leaching losses and improving nutrient uptake and water pollution. Further studies are needed to explore the impacts of reduced fertilization and water-saving irrigation on leaching losses. The benefits at different climatic conditions, soil types, and fertilizer types with application methods are also a research gap.

     

无机化学肥料和农药对土壤微生物的影响初探

研究了微生物群落在实验室培养条件下对不同土壤环境所产生的变化。在实验室中模拟农田环境,并且在农药和无机肥料的影响下,观察土壤中微生物群落60 d内的功能多样性的变化。实验土壤有4种类型:无农药和化肥影响的土壤(S1);有农药杀灭菊酯和甲基托布津的影响(S2);加入(NH_4)_2HPO_4(S3);加入农药杀灭菊酯、甲基托布津和无机化学肥料(NH_4)_2HPO_4(S4)。实验用BIOLOG GN微平板鉴定系统测定四种土壤的颜色平均变化率(AWCD)值,通过比较S1、S2、S3和S4样本在不同培养天数的AWCD-时间曲线,讨论了农药和无机化学肥料对土壤微生物的影响。     

生物有机肥对轻度盐碱土理化性质影响的研究

目的:研究施用生物有机肥改善盐碱土。方法:将生物有机肥施入轻度盐碱土中,研究其对土壤理化性质的影响。结果:生物有机肥可以改善轻度盐碱土pH值,有效缓解由于植物生长所造成的土壤养分的消耗。结论:生物有机肥可在轻度盐碱土中广泛使用,在施用时应根据不同地区的土壤气候条件确定最佳施肥量。     

5种叶面肥对草莓光合特性及品质的影响

为探讨不同叶面肥对大棚草莓光合特性、果实品质及产量的影响,并筛选出适宜的叶面肥,以甘肃省兰州市西固区牟家台草莓温室大棚内栽植的草莓品种‘蒙特瑞’为试材,在施肥充足的情况下,在4个生育期追肥喷施经典750倍液（T1）、花仆1500倍液（T2)、润亮750倍液(T3)、艾德拉果500倍液（T4）及磷酸二氢钾1500倍液（T5）5种叶面肥,清水作为对照（CK）,测定了处理植株光合参数、果实品质、生物量及产量等指标。结果表明：（1）喷施不同叶面肥处理后草莓植株生物量、叶绿素含量显著增加,叶片的净光合速率和蒸腾速率显著上升,喷施叶面肥后的草莓植株胞间二氧化碳浓度均高于CK;（2）对果实品质而言,T2和T3处理能够显著改善草莓果形指数,T1和T5可以显著增大果实体积和重量。其中,T1的平均单果重较CK增加了5.89 g,T5的果实横径和纵径分别较CK增加了1.22 cm和1.15 cm。（3）实硬度、可溶性固形物含量、维生素C含量和还原糖含量有很明显的提高,并以T1施用效果最佳,较CK分别增加了3.3%、17.25 mg/g、2.71%。处理T1和T3可溶性蛋白含量分别较CK提高了0.097 mg/g和0.070 mg/g;（4）喷施叶面肥能够显著提高草莓单位面积产量,且以处理T1处理产量最高,较CK增长了13.65%。可见,施用适宜的叶面肥均能有效改善草莓营养生长状况,提升草莓果实品质,显著提高产量,并以经典750倍液叶面肥施用综合效果最佳。     

Effect of Reaction-Finished Solution of Hydrochar (HRFS) Application on Rice Grain Yield and Nitrogen Use Efficiency in Saline Soil

We conducted a pot experiment to examine the feasibility of applying a reaction-finished solution of hydrochar (HRFS) to enhance rice production in a saline soil. With this purpose, HRFS was applied (0, 10, 20, 40, 60, 80 and 100 mL/pot) and rice yield and nitrogen (N) use efficiency (NUE) were determined. HRFS application significantly (P < 0.05) increased rice grain yield by 19.6%–30.0% compared to the control treatment (CKU, with N but without HRFS addition). Moreover, HRFS application promoted plant height and straw biomass of rice. Increases of rice yield were mainly achieved by increases in the number of panicles and grains per panicle. Compared with the CKU treatment, the NUE of HRFS amendments significantly (P < 0.05) increased by 56.3%–71.7%. This indicated that the improvement of NUE was one of the mechanisms to improve rice grain yield with HRFS amendment. The results of regression analysis showed that there was a positive relationship (R²=0.8332) between rice yield and HRFS application rate within an appropriate range. The highest rice yield was recorded with the HRFS application of 40 mL/pot, but a further increase in HRFS application rate appeared to reduce rice yield. Based on the results of this pot study, HRFS application can increase rice yield in a saline soil by regulating its yield components and enhancing NUE. However, impact of HRFS on these variables showed a “dose effect”.     

Effects of Organic Resource Quality on Soil Profile N Dynamics and Maize Yields on Sandy Soils in Zimbabwe

Optimising the use efficiency of nitrogen (N) derived from different quality organic resources and mineral fertilizers on sandy soils with <100 g clay kg⁻¹ is a major challenge for smallholder farmers in Southern Africa. The dominant sandy soils have a poor capacity to store and supply crop nutrients due to low organic matter contents and inherent infertility. A study was conducted in Zimbabwe to determine the differential N supply effects of different quality and quantities of organic nutrient sources on maize productivity. Crotalaria juncea L., Calliandra calothyrsus Meissn., cattle manure, maize (Zea mays L.) stover and Pinus patula Schiede & Schltdl. & Cham. sawdust which represented high to low quality materials respectively, were each incorporated into soil at 1.2 and 4 t C ha⁻¹ at Makoholi Experiment Station (rainfall: 450–650 mm yr⁻¹) and tested against a sole mineral N fertilizer and control treatments. In a separate experiment conducted in farmers’ fields under different rainfall zones of Zimuto (450–650 mm yr⁻¹), Chinyika (650–750 mm yr⁻¹) and Chikwaka (>750 mm yr⁻¹), commonly available organic materials, including manure and composted miombo leaf litter, applied in varying amounts by farmers were evaluated. Nitrogen release patterns were consistent with differences in resource quality. At 3 weeks after incorporation into soil at the onset of the rains, C. juncea and C. calothyrsus had released as high as 24% and 13% of added N respectively, compared with no more than 5–6% for the rest of the amended treatments. Most of the N released was lost through leaching as evidenced by progressive movement of NO₃⁻-N bulges beyond maize rooting depth following major rainfall events. Maize yields were significantly related to the size of profile mineral N fluxes, with the best linear relationship (R² = 0.86) obtained with N available in the top 30 cm of soil at maize flowering. High grain yields of ~3 t ha⁻¹ were only achieved with C. juncea applied at 4 t C ha⁻¹, which also had highest NO₃⁻-N leaching losses. Conversely, the same application rate increased N immobilization by 30% and 42% under maize stover and sawdust, respectively, relative to the control. Results from farmers’ fields showed that organic resources traditionally used on smallholder farms are invariably of low quality relative to C. juncea and C. calothyrsus. However, they exhibited shorter N immobilization effects than was shown for maize stover and sawdust at Makoholi, suggesting that pre-application treatments, such as composting, employed by farmers enhance seasonal N benefits from these materials. Maize yields increased linearly with total N added in these resources in combination with N fertilizer, justifying the high organic matter loading strategy (e.g. >20 t ha⁻¹ for manure, fresh litter and composted litter) used by farmers who often achieve high crop yields on such coarse sandy soils in Zimbabwe.     

Effects of Amendments and Water Conditions on the Chemical Speciation of Cd and Pb in Contaminated Paddy Soil in a Mining Area

Lime, sepiolite and peat were used as amendments to study their effects on the chemical speciation of Cd and Pb in a polluted paddy soil under moist and water-logged conditions. The results showed that application of amendments reduced acid-extractable Cd (up to 12.56% and 5.07%) and Pb (up to 6.69% and 2.68%) in moist and water-logged soils, respectively. The reducible Cd and residual Cd was increased while the oxidizable Cd was decreased after adding amendments. However, the oxidizable Pb was increased while the residual Pb was decreased in amended soil, and the reducible Pb presented a different changing trend under moist and water-logged conditions. The soil pH was significantly correlated with different fractions of Cd and Pb in soil, which indicated a distinct influence of soil pH on the redistribution process of Cd and Pb fractions in amended soil.     

土壤有机质和外源有机物对甲烷产生的影响

对土壤有机质含量及组分、外源有机物和根系分泌对甲烷产生的影响作了综述。土壤产甲烷量和甲烷排放量随有机质含量增加而提高,与土壤中易矿化有机碳或沸水浸提有机碳含量呈显著相关。外源有机碳加入促进了土壤排放甲,刺激效果与外源有机碳的用量和组成有关。还原力强的有机物如纤维素和半纤维素较还原力弱的有机物如类脂和多糖能够产生更多的甲烷。甲醇、甲基化氨基酸等无其它微生物竞争利用的有机物能被产甲烷菌更多地转化成甲烷。植物根系分泌物也促进甲烷的产生,促进作用大小与植物种类及分泌物的数量和质量有关。外源有机物通过3种方式促进土壤甲烷产生;提高土壤的甲烷底物供应量,降低土壤氧化还原电位,刺激土壤原有有机碳的转化。     

土壤活性有机碳的表征及其生态效应

土壤活性有机碳指在一定的时空条件下,受植物、微生物影响强烈、具有一定溶解性、在土壤中移动比较快、不稳定、易氧化、分解、易矿化,其形态,空间位置对植物、微生物来说活性比较高的那一部分土壤碳素。国外描述这一部分碳素的术语为有效碳、水溶性碳、易氧化碳、可矿...     

硬覆盖对土壤水热传输及作物生长发育影响的试验研究

河北省盐渍区农业水资源非常紧缺 ,农业节水势在必行。覆盖保摘技术是农田节水管理的重要措施之一 ,国内外对此有过不少研究报道。但多集中在地膜、秸秆、砂砾和化学喷涂等覆盖材料上 ,这些覆盖材料在使用中有种种不理想之处 ,如地膜覆盖容易造成残膜的“白色污染” ,并且使用年限短 ,降水不易入渗 ,中耕、除草、施肥困难 ,使作物抗病力差等[1 ] ;秸秆覆盖容易使秸秆中的毒素物质与作物间发生生化它感现象 ,影响作物生长[2 ] 。化学喷涂除了不利于农事作业外 ,还可能造成土壤污染。为此 ,我们在中国科学院南皮试区盐渍土上试用了一种新型覆…     

土壤水分对翅果油树幼苗生理生化特性的影响

通过盆栽试验,研究了土壤水分含量对翅果油树幼苗地上部分和根系生物量和含水量,以及叶片保水力、相对电导率和保护酶活性的影响.结果表明:与对照(处理前)相比,各土壤水分条件下翅果油树幼苗叶片保水力均降低,而叶片相对电导率(REC)、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性均升高.随着土壤含水量的降低,幼苗地上部分和根系的生物量、含水量及叶片保水力均呈先升高后降低的趋势,而叶片REC、SOD和POD活性均呈先降低后升高趋势,并均以轻度干旱胁迫处理(田间持水量的55%~60%)的REC、SOD和POD活性最低,而叶片保水力最高.在相同土壤水分条件下,随着处理时间的延长,叶片REC逐渐升高,而叶片保水力降低,SOD和POD活性先升后降并以处理10d时活性最高.研究发现,在轻度干旱胁迫下,翅果油树幼苗能协调其保护酶系统降低干旱伤害,维持正常生长,表现出一定的抗旱能力.     

Effects of Soil Water Content on Biodegradation of Phenanthrene in a Mixture of Organic Contaminants

Phenanthrene biodegradation was investigated at different soil water contents [0.11, 0.22, 0.33, 0.44 g H₂O (g soil)^?1] to determine the effects of water availability on biodegradation rate. A subsurface horizon of Kennebec silty loam soil was used in this study. [9-¹⁴C] phenanthrene was dissolved in a mixture of organic contaminants that consisted of 76% decane, 6% ρ-xylene, 6% phenanthrene, 6% pristane, and 6% naphthalene, and then added to the soil. The highest rate of mineralization, in which 0.23% of the [9-¹⁴C] phenanthrene degraded to ¹⁴CO₂ after 66 days of incubation, was observed at the soil water content of 0.44 g H₂O/g dry soil. Most of the ¹⁴C remained in the soil as the parent compound or as nonextractable compounds by acetonitrile at the highest water content. Concentrations of nonextractable compounds increased with water content, but residual extractable phenanthrene decreased significantly with increasing water content, which presumably indicates that bio-transformation occurred. The mineralization analysis of radiolabeled 9th carbon in phenanthrene underestimated phenanthrene biodegradation. The strong adsorption and low solubility of phenanthrene contributed to the low mineralization of phenanthrene 9th carbon. The other components were subject to higher biological and abiotic dissipation processes with increasing soil water content.     

不同施肥方案对芒果果实品质与土壤肥力的影响

以海南贵妃芒Mangifera indica ‘Guifei’为试材,在化肥、有机肥施用量上设置3个不同处理,研究不同施肥方案对芒果果实品质及土壤肥力的影响。结果表明,与单施化肥比较,T1和T2处理使果实可溶性固形物含量提高12.0%～22.1%,维生素C含量提高8.5%～28.5%,可滴定酸含量下降41.2%～42.4%,固酸比提高94.4%～107.5%;与对照相比,本研究中提供的施肥处理显著提高土壤有机质、全氮、有效磷、速效钾、交换性钙、交换性镁、电导率及pH值,提升土壤肥力。综合而言,T2处理(有机肥5 kg·株^-1 + 尿素385 g·株^-1 + 过磷酸钙350 g·株^-1 + 高钾复合肥700 g·株^-1)对改善果实品质和改良土壤肥力性状效果最佳。     

秸秆还田与施肥对土壤酶活性和作物产量的影响

通过大田定位试验,在小麦-玉米轮作条件下,以小麦品种‘西农889’和玉米品种‘郑单958’为供试作物,采取不施肥秸秆不还田(CK)、秸秆还田(S)、秸秆还田+腐熟有机肥(SM)、秸秆还田+氮肥(SN)、秸秆还田+氮肥+磷肥(SNP)共5种处理,对不同处理下土壤电导率、蔗糖酶活性和脲酶活性的动态变化及作物产量进行了研究。结果显示:(1)秸秆还田后土壤的电导率变化呈先上升后下降趋势,不同处理间周年电导率平均值表现为SNP>SN>SM>S>CK,且差异显著。(2)秸秆还田配合施用氮肥处理的土壤蔗糖酶活性和脲酶活性最高,蔗糖酶活性最大值(70.62mg.g-1.d-1)为对照的1.36倍,脲酶活性最大值(3.58mg.g-1.d-1)比对照提高了9.15%。(3)土壤有机碳含量在S、SM处理之间差异不显著,而S、SM处理与CK、SN、SNP处理之间差异显著,SM处理比对照处理提高了8.91%。(4)土壤全氮含量在不同处理之间差异显著,并以SNP处理最高,其次是SM处理,S、SN处理再次之,且SNP、SM、S、SN处理土壤全氮含量分别比对照提高了19.8%、11.1%、9.88%和7.41%。(5)秸秆还田处理的作物产量显著高于CK,并以秸秆配施氮磷肥处理的小麦产量最高,比CK提高了50.6%;秸秆配施氮肥处理的玉米产量最高,比CK提高了34.3%。研究表明,秸秆还田配施有机肥、无机肥可以有效促进有机物矿质化,显著增加土壤养分含量,增强土壤酶活性,提高土壤有机碳含量,从而促进作物增产。     

不同肥料对土壤养分三要素平衡与累积的影响

本文探讨不同肥料、施肥结构、施肥方法对土壤养分三要素平衡与累积的影响。结果表明,不同形态单位氮素投入对土壤氮素盈余影响为猪粪> 化肥> 稻草,对土壤全氮提高的影响为稻草> 化肥> 猪粪;不同形态单位磷素投入对土壤磷素盈余的影响为猪粪> 化肥> 稻草,对土壤全磷提高的影响为化肥> 猪粪> 稻草;不同形态单位钾素投入对土壤钾素盈余影响为化肥> 猪粪> 稻草,对缓解土壤钾素下降的影响为猪粪> 稻草> 化肥。     

连续炭基肥替代化肥对菜园土壤性质和细菌群落结构的影响

为了解生物炭基肥替代化肥减量施用的田间长期效应,利用定位试验研究连续5 a炭基肥替代化肥对蔬菜产量、土壤理化性质和细菌群落结构的影响。结果表明,连续5 a实施炭基有机肥替代化肥,土壤p H提高了0.13～0.25,土壤有机质、碱解氮和有效磷含量也分别提高了2.1%～62.2%、5.8%～86.0%和0.4%～103.1%,炭基肥替代化肥处理的荠菜(Capsella bursapastoris)产量提高了4.0%～14.8%,但75%替代处理较50%替代处理有所降低。炭基肥替代化肥处理的土壤菌群Sobs、Shannon、Ace和Chao指数均高于单施化肥处理,且均以75%替代处理最高。炭基肥替代化肥显著降低了土壤中硝化菌属(Nitrolancea)、拟无枝酸菌属(Amycolatopsis)、芽单胞菌属(Gemmatimonas)等的丰度,增加了纤维素降解菌菌群(Planifilum、Saccharomonospora)的丰度。芽单胞菌属、Ilumatobacteraceae、Methyloligellaceae等的丰度与土壤全氮、全磷、有机质间具有显著的相关性。可见,连续炭基肥替代化肥...     

渭北旱塬苹果园不同水肥管理模式下的土壤水分差异

为了探究渭北旱塬苹果园不同水肥管理模式下的土壤水分差异,于2013—2016年在地处渭北旱塬的陕西省白水县田家洼村进行了田间试验,设置了3个不同果园水肥管理方式:农户模式(单施化肥,FM)、现有模式(推荐施肥配合地膜覆盖,EM)、优化模式(有机无机肥配施配合双元覆盖,OM),并对0~300 cm土层土壤水分进行了测定.结果表明:优化模式可以显著提高0~200 cm土层土壤贮水量,0~100 cm土层土壤含水量在干旱季节较农户模式和现有模式分别增加5.6%和15.3%,优化模式200~300 cm土层土壤水分相对亏缺指数低于现有模式,在干旱年份可以提高降雨入渗,降雨入渗达到300 cm,同时优化模式可以提高果园0~300 cm土层土壤降水补充量,稳定土壤水分变化,有效缓解了深层土壤干燥化程度.优化模式4年平均产量较农户模式和现有模式分别提高36.6%和22.5%.综上,优化模式可以通过提高土壤有效含水量,改善浅层和深层水分状况,提升土壤水分利用效率,在提高产量的同时,缓解土壤深层干燥化程度.     

子午岭林区生态系统转换对土壤有机碳特征的影响

生态系统转换影响土壤有机碳的动态、循环及环境质量.本研究分析了子午岭林区农田、草地、灌丛和森林不同生态系统土壤总有机碳、活性有机碳和稳定性有机碳含量.结果显示:各生态系统中,表层(0~10 cm)土壤总有机碳含量显著高于深层土壤(40~70 cm).与农田生态系统表层土壤相比,草地、灌丛、森林生态系统土壤总有机碳含量分别增加82.07%、121.67%和183.16%,深层土壤有机碳含量也有类似的趋势;从增加的绝对值来看,表层土壤活性有机碳含量分别增加2.24、4.13和5.43 g/kg,土壤稳定性有机碳含量分别增加4.76、6.23和10.18g/kg.表明农田生态系统转换为林、草生态系统,有利于土壤有机碳的积累.而且,土壤作为碳“汇”的功能增强,更有利于CO2固定和生态环境改善.     

不同有机肥配施对小麦和燕麦镉积累、分配及转运的影响

为探讨化肥减量配施不同有机肥对小麦和燕麦镉吸收变化特征。试验在化肥施用减量20%基础上,设厩肥30000 kg/hm2（AM）、生物有机肥600 kg/hm2（BF）、厩肥30000 kg/hm2+生物有机肥600 kg/hm2（AM+BF）及化肥正常施用量（CK）4个施肥处理,研究不同有机肥对作物镉积累、分配、转运影响。结果显示,有机肥配施可降低作物各器官镉吸收,与CK相比,小麦籽粒镉含量降低15.79%-36.84%,籽粒富集系数降低8.02%-24.55%,根、茎、叶、穗向籽粒的转运系数降低5.79%-56.28%;与CK相比,燕麦籽粒镉含量降低11.76%-47.06%%;处理BF、AM+BF籽粒富集系数降低38.46%、30.77%%;根、茎、叶、穗向籽粒的转运系数降低16.2%-32.77%;并且灌浆后燕麦籽粒镉含量上升伴随着茎镉含量下降。有机肥配施处理下两种作物生物量增加6.78%-11.00%;燕麦抽穗后各器官镉向籽粒的转移量、转移率、贡献率均以茎为最高。上述结果表明,配施有机肥可降低作物籽粒镉含量、富集系数和转运系数,可提高农产品安全质量,且对燕麦籽粒降镉效果优于小麦,研究发现作物抽穗后镉从茎向籽粒转运是籽粒镉积累的主要来源。