生物炭和其他有机土壤改良剂对Ustoxic Quartzipsamment土壤上植物养分有效性的影响

A sandy soil, Nampong soil(classified as Ustoxic Quartzipsamment), was incubated under controlled condition i) to compare the mineralization of major plant nutrients derived from different types of biochars and other organic soil amendments; ii) to examine their effects on soil properties and plant nutrient availability; and iii) to evaluate the plant nutrient losses in leachate from the rooting zone of soil incorporated with the different amendments. The experiment was arranged in a completely randomized design with 3 replications.Five treatments of soil amendments used were cassava stem base biochar(CSB), rice husk biochar(RHB), chicken manure(CM),compost(CP), and no amendment application(control). The RHB treatment released the highest amounts of mineralized NO-3-N,available P and K(2.30–17.26, 5.50–42.90 and 43.00–187.63 mg kg-1, respectively) while the CM treatment releasing the highest NH+4-N in the range of 1.86–53.67 mg kg-1. The CSB and RHB treatments showed better continuity of mineralization of nutrients than the treatments of CM and CP, particularly in the case of the CSB treatment. In the soil column incubation experiment, the amounts of NH+4-N and NO-3-N in all treatments barely changed on Day 1 to Day 30 of incubation and then the amounts increased markedly on Day 60. On Day 60, the RHB treatment contained a very high amount of NO-3-N( 250 mg kg-1). This suggests that N would become more available 30 d after the incorporation. The CM treatment gave the highest amounts of organic matter and available P in the ranges of 4.64–8.94 g kg-1and 14.41–36.33 mg kg-1, respectively, during the 60-d column incubation. The CSB treatment tended to have higher available K throughout the measuring period. The NO-3-N was leached from the soil column quite quickly on Day 1 of incubation while the loss of NH+4-N decreased slightly from Day 1 until the end of the measurement. The amounts of P and K losses varied with the type of soil amendments, and the pattern of the loss was irregular.     

Nitrogen transformation from three soil organic amendments in a sandy soil

Abstract

A sandy soil was amended with various rates (20 – 320 g air-dry weight basis of the amendments per kg of air-dry soil) of chicken manure (CM), sewage sludge (SS), and incinerated sewage sludge (ISS) and incubated for 100 days in a greenhouse at 15% (wt/wt) soil water content. At the beginning of incubation, NH₄-N concentrations varied from 50 – 280 mg kg^?1 in the CM amended soil with negligible amounts of NO₃-N. Subsequently, the concentration of NH₄-N decreased while that of NO₃-N increased rapidly. In soil amended with SS at 20 – 80 g kg^?1 rates, the NO₃-N concentration increased sharply during the first 20 days, followed by a slow rate of increase over the rest of the incubation period. However, at a 160 g kg^?1 SS rate, there were three distinct phases of NO₃-N release which lasted for160 days. In the ISS amended soil, the nitrification process was completed during the initial 30 days, and the concentrations of NH₄-N and NO₃-N were lower than those for the other treatments. The mineralized N across different rates accounted for 20 – 36%, 16 – 40%, and 26 – 50% of the total N applied as CM, SS, and ISS, respectively.     

Effects of four organic amendments on banana parasitic nematodes and soil nematode communities

Plant–parasitic nematodes are injurious crop pests that have been managed mainly by chemical nematicides. However, safe and alternative methods such as those based on organic materials need to be developed. Our study has evaluated (i) the effects of four organic amendments with different biochemical compositions that are abundantly produced in the study area (Guadeloupe, French West Indies) on soil nematode communities and (ii) some of the suppression mechanisms of banana parasitic nematodes, especially those involving the soil food web. This study is based on a microcosm experiment comparing sugarcane bagasse, sugarcane sludge, plant residues and sewage sludge. All amendments except sewage sludge decreased the root abundances of plant–parasitic nematodes, by 96% in the case of sugarcane bagasse. For this treatment, soil densities of carnivorous nematodes were six times higher than the treatments without organic amendment. Plant residues and bagasse were mainly composed of materials that are difficult to decompose, namely cellulose and lignins. These organic materials favored a fungal decomposition pathway and permitted development of carnivorous nematode populations and increased the Channel Index (CI). Pratylenchus coffeae control after sugarcane refinery sludge application remains unexplained. Lastly, sewage sludge, composed mainly of easily degradable compounds, did not permit nematode control, and only bacterivorous nematode populations were enhanced by this treatment.     

土壤改良剂和有机肥对旱改水砖红壤稻田的改良效果

针对旱改水稻田土壤酸化和土地贫瘠的问题,探究土壤改良剂和有机肥对旱改水砖红壤稻田的改良效果,以期为南方砖红壤地区旱改水农田土壤改良提供科学依据和技术指导。通过大田试验,采用正交试验设计,设置土壤改良剂种类(石灰、硅钙钾镁和草木灰)和用量、有机肥种类(秸秆、羊粪和混合发酵有机肥)和用量的处理,测定各处理土壤 pH值、有机质含量、微生物数量以及土壤氮、磷、钾养分含量。结果表明,水稻种植 15 d后,施用硅钙钾镁能显著提高土壤 pH值,但提升幅度较小。施用秸秆、羊粪和混合发酵有机肥均能显著提升土壤 pH值、有机质含量、微生物总量和土壤氮、磷、钾含量。当有机肥施用总量超过 90 t/hm²时,田间水稻倒伏率随有机肥施用量的增加而显著上升。因此,施用有机肥是旱改水稻田土壤改良的有效措施,但土壤改良和地力提升需循序渐进,不宜一次性过量施用有机肥,最佳施用量为 90 t/hm²。     

Nutrient dynamics from surface-applied organic matter amendments on no-till orchard soil

Advancing conservation agriculture depends on understanding nutrient dynamics of organic matter amendments (OMA) on no-till soil. This field incubation study compared surface-applied composted dairy manure (CM), green waste compost (GWC) and an unamended control from March to September in 2015 and 2016 using a RCBD in a California almond (Prunus dulcis) orchard. Measurements included OMA nutrient release rates, changes in soil organic carbon (SOC), total N (TN) and inorganic N, P and K availability using in-season soil sampling and collection of ion exchange resin (IER) membranes from 0 to 10 cm depth, and cumulative N and P availability using soil IER cores from 0 to 50 cm depth. We hypothesized OMA sources with a lower initial C:N increase soil N availability, greater soluble phosphorus (P) and potassium (K) concentrations increase P and K availability, and all OMA sources increase SOC with the greatest N recovery in the TN pool. No differences were observed in C, N and P release rates, while the K release rate was the greatest. In-season N availability showed no effect but P and K availability differed as evidenced by greater IER adsorption and soil extractable P and K. Both OMA sources significantly increased in SOC and TN. Net N mineralization from OMA sources ranged from 0.7% to 8.0% of applied N and total N recovery in TN and inorganic N pools increased based on the initial C:N. These results advance our understanding of nutrient dynamics while conserving the soil due to the no-till practice of surface-applied OMA.     

Effects of long-term application of various organic amendments on soil particulate organic matter storage and chemical stabilisation of vertisol soil

Current understanding of the effects of long-term application of various organic amendments on soil particulate organic matter (POM) storage and chemical stabilisation remains limited. Therefore, we collected soil samples from the soil profile (0–100?cm) under six treatments in a 31-year long-term fertilisation experiment: no fertiliser (CK), mineral fertilisers (NPK), mineral fertilisers plus 3.8 or 7.5?t?ha^?1?year^?1 (fresh base) the amount of wheat straw (1/2SNPK and SNPK) and mineral fertilisers plus swine or cattle manure (PMNPK and CMNPK). Long-term incorporation of wheat straw and livestock manure amendments significantly (p?<?0.05) increased crop yield and sustainable yield index, and POM storage compared with CK and NPK treatments. The mole ratios of H/C in the POM under organic amendment treatments significantly (p?<?0.05) decreased by 13.8% and 37.1%, respectively, compared with the NPK treatment. Similarly, solid state NMR spectroscopy showed that the O–alkyl carbon content of POM was greatly decreased, whereas aromatic carbon contents and alkyl to O–alkyl carbon ratios were substantially increased under PMNPK and CMNPK treatments. In conclusion, we recommend long-term livestock manure application as a preferred strategy for enhancing POM quantity and quality (chemical stability), and crop yield of vertisol soil in northern China.     

连续施用土壤改良剂对砂质潮土团聚体及作物产量的影响

  【目的】   研究施用无机和有机土壤改良剂对团聚体形成和作物产量的影响,为新型土壤改良剂的应用提供理论依据。   【方法】   以河北廊坊砂质潮土为研究对象,以虾头蟹壳废弃物为核心材料的有机土壤改良剂 (SC) 和以凹凸棒土为核心材料的无机土壤改良剂 (SA) 为试材,进行4年 (2015—2019) 定位试验。试验设4个处理:单施化肥 (CK)、化肥+无机改良剂 (SA)、化肥+有机改良剂 (SC)、化肥+无机改良剂+有机改良剂 (SCA)。种植方式为小麦–玉米轮作。2019年小麦和玉米收获后,测定作物产量并采集耕层土壤,测定土壤理化指标、微生物量碳氮含量、团聚体组成及其碳氮含量。   【结果】   在小麦季和玉米季,SCA处理均可显著提高作物产量,较CK处理分别提高了54.16%和24.26%;在小麦季,SC处理较CK处理显著提高土壤全氮 (TN)、有机碳 (SOC)、速效钾 (AK) 和有效磷 (AP) 含量,微生物量碳 (MBC) 显著提高8.82%,pH显著降低3.19%;在玉米季,SCA处理较CK显著提高了土壤TN、SOC、AK、AP含量,MBC显著提高了33.65%,土壤pH显著降低了5.92%;在小麦季和玉米季,土壤团聚体均以粒径0.053～0.25 mm为主;与CK处理相比,小麦季SC处理土壤粒径 > 0.25 mm的大团聚体含量、平均重量直径 (MWD) 和几何平均直径 (GMD) 分别显著提高42.51%、22.41%和20.35%,玉米季SCA处理3个指标分别显著提高68.71%、35.47%和29.65%;各粒级团聚体中SOC和TN含量都以粒径 > 0.25 mm大团聚体最高,且SCA处理显著增加土壤各级别团聚体SOC和TN含量;施用土壤改良剂增加粒径 > 0.25 mm大团聚体SOC和TN贡献率,小麦季SC处理较CK处理分别增加了29.06%和69.24%,玉米季SCA处理较CK处理分别增加了61.62%和114.20%;通过冗余分析和结构方程模型分析发现,粒径> 0.25 mm大团聚体与pH呈负相关关系,与AP、MBC、SOC以及各粒级团聚体中碳含量呈正相关关系;稳定的团聚体结构会影响SOC含量和pH,改善土壤C/N,进而影响作物产量。   【结论】   在砂质土壤上,单独施用以虾头蟹壳废弃物为核心材料的有机土壤改良剂或与无机土壤改良剂配施均可改善土壤理化性质,促进大团聚体形成,提高团聚体稳定性,稳定的土壤团聚体可通过改善土壤碳氮比以提高作物产量。     

Effects of organic amendments on soil carbon sequestration in paddy fields of subtropical China

Purpose  

Although organic amendments have been recommended as one of the practices for crop production and soil carbon sequestration, little has been done to evaluate soil organic carbon (SOC) dynamics following long-term application of organic amendments. The objective of this research were to (1) assess the effect of long-term organic amendments on SOC dynamics in rice-based systems; (2) evaluate the relationship between soil carbon sequestration and carbon input based on various mineral and organic fertilization treatments.     

Soil organic matter evolution after the application of high doses of organic amendments in a Mediterranean calcareous soil

Purpose

We investigate the coevolution of soil organic matter (SOM) and soil properties in a semiarid Mediterranean agroecosystem, as well as the 1-year evolution of the different pools of soil organic and inorganic carbon and their influence on soil respiration after the application of a single high dose of three different organic amendments.

Material and methods

We applied a single high dose (160?Mg?ha^?1 in dry weight (DW)) of three types of organic amendments: aerobically digested sewage sludge (AE), anaerobically digested sewage sludge (AN), and municipal solid waste compost (MSWC), in a calcareous Mediterranean soil. The study area is located in the southeast of Madrid (Spain), characterized by a Mediterranean climate with a marked seasonal and daily contrast. We analyzed different forms of soil organic and inorganic carbon and soil respiration rates. The measurements have been performed quarterly for 1?year.

Results and discussion

The results showed that the coevolution of SOM and soil largely depends on the origin and composition of the organic amendments used. The AN sludge affected the soil chemistry more. The organic matter (OM) provided by AE treatments underwent more intense mineralization processes than AN, with the OM from MSWC being more stable. This behavior could be explained by the different pools of carbon involved in each case. The treatments contributed differently to soil respiration rates following the sequence: AE > AN > MSWC. The application of organic amendments in calcareous Mediterranean soils also modified the inorganic carbon pools.

Conclusions

SOM and soil coevolution after organic amendments application depends on the origin and chemical composition of the inputs. The decision-making process of urban organic waste application with regard to agricultural policy must take into account the different behavior in soil of the different types of amendments.     

Biochemical quality of organic amendments affects soil fungistasis

Soilborne plant pathogens are among the most important limiting factors for the productivity of agro-ecosystems. Identifying reliable and effective control methods is crucial for efficient biological control. Soil fungistasis is the capability of soils to inhibit the germination and growth of soil-borne fungi in presence of optimal abiotic conditions. The aim of this study is to clarify the relationships between soil amendments with plant residues spanning a wide variety of biochemical quality and soil fungistasis. Microcosms experiments were performed with 42 different plant residues and the effect on soil fungistasis was assessed by using four different fungi (Aspergillus niger, Botrytis cinerea, Pyrenochaeta lycoperici and Trichoderma harzianum). We measured soil respiration and FDA enzymatic activity and compared classic litter proximate chemical analysis with ¹³C-CPMAS NMR spectroscopy. Results showed that quality of organic amendments is a major controlling factor of soil fungistasis. The dramatic relief of soil fungistasis when soil was amended with lignin poor, but labile C rich, substrates gives strong support to the competition-based hypothesis. The positive correlation between soil respiration and fungal growth further supports the competition hypothesis. Finally, ¹³C NMR results showed a relationship between soil fungistasis and the biochemical quality of plant residues, and provided a quantitative assessment of the time required for fungistasis restoration after organic materials application.     

废水灌溉下有机物料对重度盐渍土养分及芦苇生长的影响

在山东滨州含盐量为16.7 g.kg 1的重度退化滨海盐碱湿地,研究了造纸废水灌溉条件下添加有机物料对盐渍土养分和芦苇生长的影响,以期为重度退化滨海盐碱湿地的生物修复提供依据。试验从春季开始进行,共设4种处理:翻耕对照(CK)、翻耕+废水灌溉(FF)、翻耕+废水灌溉+秸秆(FFJ)以及翻耕+废水灌溉+污泥(FFW),测定了不同处理下土壤养分、呼吸强度、含盐量及芦苇株高和生物量的变化。结果表明,与对照相比,各处理土壤有机质显著提高,10月末时FFJ、FFW和FF处理土壤有机质含量分别是对照的1.34倍、1.29倍和1.22倍;碱解氮和有效磷含量也高于对照,依次为FFW>FFJ>FF>CK;各处理土壤呼吸强度高于对照,其中FFJ处理显著高于对照,比试验初期提高96%;各处理表层土壤含盐量均出现不同程度降低,以FFJ和FFW降低幅度最大,分别比对照降低22.6%和16.3%;FFW、FFJ和FF处理的芦苇株高显著高于对照,8月末分别是对照的3.1倍、2.7倍和2.2倍;FFJ和FFW处理的芦苇生物量、根冠比和平均叶面积都显著高于对照,而FF处理与对照没有显著差异;FF处理芦苇株高、生物量与土壤有效氮含量相关最为显著,FFJ和FFW处理与土壤有机质含量相关性最为显著。结果表明,废水灌溉为重度盐渍化土壤提供了充足的水分,有机物料能有效提高土壤养分含量,解决了重度盐碱化土壤水分胁迫和养分胁迫的问题,促进芦苇生长,但秸秆和污泥两种有机物料之间没有显著差异。     

Immobilization of soil copper using organic and inorganic amendments

This experiment aimed to immobilize Cu in polluted agricultural soils via the application of agrochemicals to reduce its bioavailability to plants. A greenhouse pot experiment was established using a Cu contaminated vineyard topsoil collected from a farm in Greece. The soil was mixed with inorganic [i.e., zeolite (Z), Al‐oxide (AX), Mn‐oxide (MX), and phosphate rock (PR)] as well as organic amendments [i.e., activated charcoal (AC), commercial peat soil material (CP), and compost from olive oil processing wastes (COW)] with an application rate of 2.5% and cultivated by corn (Zea maize). After plant harvesting, Cu was measured separately in the aboveground biomass and roots, respectively, whereas the soil samples were analyzed for DTPA‐extractable and geochemical fractions of Cu (soluble + exchangeable fraction, sorbed and carbonate fraction, Fe‐/Mn‐oxides fraction, and organic fraction). The immobilizing agents, except MX, reduced the soluble plus exchangeable Cu in the treated soil. The lowest concentrations of the soluble plus exchangeable Cu occurred in the soil amended with AC followed by CP, AX, COW, PR, and Z, respectively. The amendments decreased the uptake of Cu by corn. Concentrations of Cu were between 11 and 38% lower in the above ground biomass and 19 and 48% lower in the roots than the control. The organic amendments were more effective than the inorganic additives. The AC was the most effective organic additive and AX was the most effective inorganic amendment.     

添加生物质炭对红壤水稻土有机碳矿化和微生物生物量的影响

通过室内培育试验,研究了添加生物质炭对江西红壤水稻土有机碳矿化和微生物生物量碳、氮含量的影响。结果表明:红壤有机碳矿化速率在培育第2天达最大值后迅速降低,培养7天后下降缓慢并趋于平稳;添加生物质炭降低了土壤有机碳的矿化速率和累积矿化量,培养结束时,不加生物质炭的对照处理中有机碳的累积矿化量分别比添加0.5%和1.0%生物质炭的处理高10.0%和10.8%。此外,生物质炭的加入显著提高了土壤微生物生物量,添加0.5%生物质炭处理的土壤微生物生物量碳、氮含量分别比对照高111.5%～250.6%和11.6%～97.6%,添加1.0%生物质炭处理的土壤微生物生物量碳、氮含量分别比对照高58.9%～243.6%和55.9%～110.4%。相同处理中,干旱的水分条件下(40%田间持水量)微生物生物量要高于湿润的水分条件(70%田间持水量)。同时,添加0.5%和1.0%的生物质炭使土壤代谢熵分别降低2.4%和26.8%,微生物商减少了43.7%和31.7%。     

Contribution of organic amendments to soil organic matter detected by thermogravimetry

Sustainable soil management requires reliable and accurate monitoring of changes in soil organic matter (SOM). However, despite the development of improved analytical techniques during the last decades, there are still limits in the detection of small changes in soil organic carbon content and SOM composition. This study focused on the detection of such changes under laboratory conditions by adding different organic amendments to soils. The model experiments consisted of artificially mixing soil samples from non‐fertilized plots of three German long‐term agricultural experiments in Bad Lauchstädt (silty loam), Grossbeeren (silty sand), and Müncheberg (loamy sand) with straw, farmyard manure, sheep faeces, and charcoal in quantities from 3 to 180 t ha^?1 each. In these mixtures we determined the organic carbon contents by elemental analysis and by thermal mass losses (TML) determined by thermogravimetry. The results confirmed the higher reliability of elemental analysis compared to TML for organic carbon content determination. The sensitivity of both methods was not sufficient to detect the changes in organic carbon content caused by small quantities of organic amendments (3 t ha^?1 or 0.1–0.4 g C kg^?1 soil). In the case of elemental analysis, the detectability of changes in carbon content increased with quantities of added amendments, but the method could not distinguish different types of organic amendments. On the contrary, the based on analysis of degradation temperatures, the TML allowed this discrimination together with their quantitative analysis. For example, added charcoal was not visible in TML from 320 to 330°C, which is used for carbon content determination. However, increasing quantities of charcoal were reflected in a higher TML around 520°C. Furthermore, differences between measured (with TML_110–550) and predicted mass loss on ignition using both organic carbon (with TML₃₃₀) and clay contents (with TML₁₄₀) were confirmed as a suitable indicator for detection of organic amendments in different types of soils. We conclude that thermogravimetry enables the sensitive detection of organic fertilizers and organic amendments in soils under arable land use.     

Influence of organic and mineral amendments on microbial soil properties and processes

Microbial diversity in soils is considered important for maintaining sustainability of agricultural production systems. However, the links between microbial diversity and ecosystem processes are not well understood. This study was designed to gain better understanding of the effects of short-term management practices on the microbial community and how changes in the microbial community affect key soil processes. The effects of different forms of nitrogen (N) on soil biology and N dynamics was determined in two soils with organic and conventional management histories that varied in soil microbial properties but had the same fertility. The soils were amended with equal amounts of N (100 kg ha⁻¹) in organic (lupin, Lupinus angustifolius L.) and mineral form (urea), respectively. Over a 91-day period, microbial biomass C and N, dehydrogenase enzyme activity, community structure of pseudomondas (sensu stricto), actinomycetes and α proteobacteria (by denaturing gradient gel electrophoresis (DGGE) following PCR amplification of 16S rDNA fragments) and N mineralisation were measured. Lupin amendment resulted in a two- to five-fold increase in microbial biomass and enzyme activity, while these parameters did not differ significantly between the urea and control treatments. The PCR–DGGE analysis showed that the addition of mineral and organic compounds had an influence on the microbial community composition in the short term (up to 10 days) but the effects were not sustained over the 91-day incubation period. Microbial community structure was strongly influenced by the presence or lack of substrate, while the type of amendment (organic or mineral) had an effect on microbial biomass size and activity. These findings show that the addition of green manures improved soil biology by increasing microbial biomass and activity irrespective of management history, that no direct relationship existed among microbial structure, enzyme activity and N mineralisation, and that microbial community structure (by PCR–DGGE) was more strongly influenced by inherent soil and environmental factors than by short-term management practices.     

Influence of inorganic fertilizers and organic amendments on soil organic matter and soil microbial properties under tropical conditions

 Soil organic matter level, mineralizable C and N, microbial biomass C and dehydrogenase, urease and alkaline phosphatase activities were studied in soils from a field experiment under a pearl millet-wheat cropping sequence receiving inorganic fertilizers and a combination of inorganic fertilizers and organic amendments for the last 11 years. The amounts of soil organic matter and mineralizable C and N increased with the application of inorganic fertilizers. However, there were greater increases of these parameters when farmyard manure, wheat straw or Sesbania bispinosa green manure was applied along with inorganic fertilizers. Microbial biomass C increased from 147 mg kg^–1 soil in unfertilized soil to 423 mg kg^–1 soil in soil amended with wheat straw and inorganic fertilizers. The urease and alkaline phosphatase activities of soils increased significantly with a combination of inorganic fertilizers and organic amendments. The results indicate that soil organic matter level and soil microbial activities, vital for the nutrient turnover and long-term productivity of the soil, are enhanced by use of organic amendments along with inorganic fertilizers. Received: 6 May 1998     

Effect of organic and inorganic soil nitrogen amendments on mouldboard plow draft

A long-term field experiment with continuous corn, corn–soybean, and corn–alfalfa rotations, and different organic and inorganic soil nitrogen amendments was established at Ottawa, Ont., in 1991. Amendments applied to continuous corn were none, inorganic fertilizer at 100 and 200 kg N ha⁻¹, stockpiled and rotted manure, each at 50 and 100 Mg ha⁻¹ (wet weight). Amendments applied in the corn year to the 2-year rotations were none, inorganic fertilizer at 100 kg N ha⁻¹, and stockpiled and rotted manure at 50 Mg ha⁻¹. Mouldboard plow draft and tractor fuel consumption measurements were made with Agriculture and Agri-Food Canada’s instrumented research tractor in conjunction with normal fall tillage in 1991 prior to amendment application, and for 4 years from 1996 to 1999.

Results showed a small difference among the amendment treatments in 1996 and 1997, and a much larger difference in 1998 and 1999. After 8 years of amendment application, plots receiving the manure amendments at the high rates exhibited from 27 to 38% lower plow draft and 13 to 18% lower tractor fuel consumption than those receiving the inorganic fertilizer. The difference was less for plots receiving the lower manure rates. The same trend occurred in the 2-year rotation plots where manures were applied in alternate years, although, the differences were much lower, and not always significant. The data clearly show that changes in soil structure and organic matter accompanying repeated applications of manure are manifested in reduced tillage energy.     

Effect of Polyacrylamide integrated with other soil amendments on runoff and soil loss: Case study from northwest Ethiopia

Anionic polyacrylamide (PAM) has the potential to reduce soil erosion through soil conditioning. However, a comprehensive study about its effectiveness especially when applied combined with other amendments have rarely been conducted in the tropical highland climatic conditions, such as in Ethiopia. The study assessed the effectiveness of PAM (P = 40 kg ha^?1) alone or integrated with other soil amendments such as gypsum (G = 5 t ha^?1), lime (L = 4 t ha^?1) and biochar (B = 8 t ha^?1) on runoff and soil loss at Aba Gerima watershed in the Upper Blue Nile basin, northwest of Ethiopia, where there is high erosion-caused soil degradation. A total of 79 daily runoff and sediment data were collected from eight runoff plots (1.3m × 4m) with three replications planted with teff (Eragrostis tef) crop for two years (2018 & 2019) rainy seasons. Associated changes in soil physicochemical properties and crop growth parameters were investigated. Treatments reduced seasonal runoff by 12–39% and soil loss by 13–53%. The highest reduction in runoff was observed from P + B and PAM treatments while the highest reduction in soil loss was observed from that of P + L and PAM treatments. Integrating PAM with other amendments improved soil structural stability, moisture content, soil pH (P + L) and organic matter (P + B), leading to favorable environment for crop growth (biomass yield) and reduced runoff and soil erosion. Unlike PAM, biochar and lime amendments may need more time after application to be more effective. Hence continuing the field experiment and studying physico-chemical mechanisms for extended period will better elucidate their single or combined effectiveness over time.     

短期翻耕和有机物还田对东北暗棕壤物理性质和玉米产量的影响

构建适宜作物生长的耕层是解决农田土壤耕层变浅、变薄、变硬和透气透水性差的重要技术途径之一,对于土壤黏粒含量较高的土壤来说,更是如此.该研究以黑龙江省较为典型的农田暗棕壤为研究对象,在黑河市爱辉农业示范园区设置不同耕层构建模式试验,分析不同翻耕深度(15、35 cm)和不同有机物还田(秸秆和牛粪)对暗棕壤物理性质、玉...