Effect of biochar amendment on soil physical,chemical and biological properties and groundnut yield in rainfed Alfisol of semi-arid tropics

The aim of this study was to evaluate the effect of biochar and organic soil amendments on soil physicochemical and microbial load, carbon sequestration potential, nutrient uptake and yield of groundnut in acidic red soil under rainfed condition. Biochar was prepared from red gram, cotton, maize stalk and mesquite wood using pilot scale slow pyrolysis biochar unit. The above sources of biochar at the rate of 2.5 and 5 t ha^?1 and enriched farmyard manure 0.75 t ha^?1, composted coir pith 10 t ha^?1 and arbuscular mycorrhizae 100 kg ha^?1 were applied as basal with required nitrogen, phosphorous and potassium fertilizer. Biochar amendment at the rate of 5 t ha^?1 reduced the bulk density from 1.41 to 1.36 g cm^?3 and increased the soil moisture 2.5%. With respect to soil chemical changes, it raised soil pH from 5.7 to 6.3; increased the cation exchange capacity 1.4 cmol⁺ kg^?1 and enhanced the carbon buildup 4.4 t ha^?1. The significant differences in bacteria, fungi and actinomycetes population were observed between biochar and control. The nitrogen, phosphorous and potassium were better utilized under biochar and composted coir pith, which was 21, 5 and 20 kg ha^?1 higher than control. The experimental results suggested that application of biochar to acidic red soil favoured good soil physical, chemical and biological environment, and these positive changes influenced growth and yield attributes and enhanced pod yield 29% over control.     

The Effect of Poultry Manure and P Fertilizer on Some Phosphorus Fractions in Some Soils of Southwestern Nigeria: An Incubation Study

An incubation experiment was conducted in the laboratory for 10 weeks to study the changes in some phosphorus (P) fractions in two soil series. Poultry manure was applied at 0, 5, 10, 15, and 20 t ha^?1 solely and in combination with single superphosphate (SSP) at 0, 15, 30, 45, and 60 kg P ha^?1. Significant increases in all the P fractions were observed to the 6th week of incubation (WAI). Sole application of poultry manure was, however, effective in reducing P occlusion in the two soil series used. An increase in Fe–P which was the largest extractable inorganic P was observed with the application of 10 t ha^?1 of poultry manure and 30 kg P ha^?1 of SSP in the Iwo series and combination of 20 t ha^?1 of poultry manure and 45 kg P ha^?1 of SSP in the Alagba series.     

Clay addition to lime-amended biosolids overcomes water repellence and provides nitrogen supply in an acid sandy soil

The addition of clay to lime-amended biosolids has been proposed as a soil amendment (LaBC^®) for remediating acidic-sandy soil. We investigated whether the presence of clay in LaBC^® altered soil microbial processes over a 30-week period. Aerobic-incubation and CO₂ respiration assays were used to monitor water repellence and chemical and microbiological properties of amended soil. Dry LaBC^® was applied at equivalent wet weight of 50, 100 and 150 t ha^?1. In addition, dry components of LaBC^® (lime, clay, lime + clay (LAC) and lime + biosolids (LAB)) were applied separately at rates equivalent to their fractions within LaBC^®. Inclusion of clay in LaBC^® was effective in eliminating water repellence at all application rates. Inclusion of clay in LaBC^® decreased nitrogen (N) release from the biosolids (by 58 %), even at 50 t ha^?1, but only during the first 2 weeks of incubation. LaBC^® consistently decreased soil microbial respiration compared with LAB alone when applied at 150 t ha^?1 thereby protecting organic matter decomposition. There was no significant N release with lime and clay amendment alone or in combination (LAC) in the absence of the biosolids. There may be a complex interaction between clay, lime and organic matter, but each may have had a role in altering N release from biosolids at different times during the 30-week incubation. Addition of clay to LAB increased its effectiveness in remediating this water-repellent, acidic-sandy soil and prolonged the N release from the biosolids following soil amendment.     

Effects of organic fertilizers on yam productivity and some soil properties of a nutrient-depleted tropical Alfisol

Field experiments were conducted at Owo, southwest Nigeria to select organic fertilizer treatments most suitable for sustaining high soil fertility and yam productivity on a nutrient-depleted tropical Alfisol. Eight organic fertilizer treatments were applied at 20 t ha^?1 with a reference treatment inorganic fertilizer (NPK 15–15–15) at 400 kg ha^?1 and natural soil fertility (control), laid out in a randomized complete block design with three replications. Results showed that organic fertilizers significantly increased (p = 0.05) tuber weight and growth of yam, soil and leaf N, P, K, Ca and Mg, soil pH and organic C concentrations compared with the NSF (control). The oil palm bunch ash + poultry manure treatment increased tuber weight, vine length, number of leaves and leaf area of yam by 66, 25, 21 and 52%, respectively, compared with inorganic fertilizer (NPK) and 37, 22, 19 and 44%, respectively, compared with poultry manure alone. Sole or mixed forms of organic fertilizers showed significant improvement in soil physical conditions compared with IF (NPK) and NSF (control). Synergistic use of oil palm bunch ash + poultry manure at 10 t ha^?1 each was most effective for sustainable management of soils and for improving agronomic productivity of yam.     

Adsorption-Desorption of Zinc as Influenced by Fly Ash in Inceptisols of Assam

This study investigates the influence of fly ash (FA) application on zinc adsorption-desorption in recommended chemical fertilizer (RDF) and farmyard manure (FYM) treatments of acidic Inceptisols of Assam. Zinc adsorption was better explained by Freundlich over the Langmuir adsorption equation. Adsorption was greatest in the treatment receiving FA only at 15 t ha^?1 and least in the treatment receiving RDF 50 percent + FYM 5 t ha^?1 + FA 5 t ha^?1. The zinc distribution coefficient of treatment FA 15 t ha^?1 was 40 to 31 times greater than treatments containing FA + RDF + FYM. The zinc supply parameter increased when FA was applied with RDF and FYM, and zinc desorption followed the order of exctractants CaCl₂ > MgCl₂ > DTPA > HCl. They desorbed more Zn from soils with low “b” and vice versa. Results confirm that fly ash integrated with RDF + FYM can effectively be used to maintain substantial concentrations of Zn in soil.     

Soil management for raising crop water productivity in rainfed production systems in Lao PDR

This study investigated the impacts of organic- and clay-based soil amendments, and their combinations on crop water productivity (CWP) using maize as a test crop. On-station field trials were established over two consecutive years at the Naphok and Veunkham sites in Laos. At each site, 10 treatments were applied in a randomized complete block design with three replications. The treatments were control, rice husk biochar (10 t ha^?1), bentonite clay (10 t ha^?1), compost (4 t ha^?1), clay-manure compost (10 t ha^?1), rice husk biochar compost (10 t ha^?1), bentonite clay + biochar, bentonite-clay + compost, biochar + compost, and bentonite clay + biochar + compost. All treatments were applied in 2011. Significant (p < 0.05) treatment effects in CWP and growing period evapotranspiration were determined. At Naphok, differences between the amended and control plots in CWP varied between 0.1 and 0.6 kg m^?3 in 2011 and from 0.1 to 0.4 kg m^?3 in 2012, whereas differences at Veunkham varied between 0.3 and 1.0 kg m^?3 in 2011 and from 0.05 to 0.29 kg m^?3 in 2012. At both sites, CWP in 2012 was significantly lower than 2011. Our results illustrate that organic- and clay-based soil amendments improve CWP, indicating that soil-based interventions could be suitable options for improving agricultural productivity.     

不同用量猪粪对红壤花生坡地水土流失和磷素流失的影响

通过田间径流微区定位试验,以中亚热带3种典型母质(花岗岩、红砂岩、红黏土)发育红壤花生坡地为研究对象,以当地常规化肥用量处理为对照,连续3年研究了在常规化肥用量减半条件下配施6个不同用量腐熟猪粪(猪粪含有0,0.5,1,2,4,8倍的对照处理磷用量)对红壤花生坡地水土流失和磷素流失的影响,以期为典型红壤地区合理施用猪粪提供科学依据。结果表明:化肥减半配施猪粪处理能有效降低红壤坡地的产流产沙,但随着猪粪用量的增加,径流水和泥沙磷含量均呈线性增加,环境风险增大。径流量和泥沙量均为花岗岩红壤红砂岩红壤红黏土红壤。配施3 500kg/(hm~2·a)猪粪,花岗岩红壤的径流量减少了28.0%、泥沙量减少了6.3%,红砂岩红壤的径流量减少了23.2%、泥沙量减少了37.1%;而配施7 000kg/(hm~2·a)猪粪,红黏土红壤的径流量减少了40.7%,泥沙量减少了12.8%。当花岗岩红壤、红砂岩红壤、红黏土红壤的猪粪用量分别达到14 000,28 000,28 000kg/(hm~2·a)时,径流水总磷平均含量超过地表水环境质量标准V类限值。径流水总磷含量为花岗岩红壤红黏土红壤红砂岩红壤,而泥沙总磷含量则为红黏土红壤花岗岩红壤红砂岩红壤。在减半化肥用量条件下花岗岩红壤和红砂岩红壤配施与常规化肥处理等磷量[P含量40kg/(hm~2·a)]的猪粪、红黏土红壤配施2倍常规化肥处理磷含量[P含量80kg/(hm~2·a)]的猪粪,可有效减少水土流失,且3年内不会增加磷素流失风险。     

Soil Quality Assessment under Restorative Soil Management Practices in Soybean (Glycine Max) after Six Years in Semi-Arid Tropical Black Lands of Central India

Vertisol soils of central India are heavy in texture, with high clay content and low organic matter. These soils are prone to degradation and the soil loss is due to poor management practices including excessive tillage. Based on a long-term study conducted for improving the quality of these soils, it was found that management practice such as low tillage (LT) + 4 t ha^?1 compost + herbicide (Hb) recorded significantly higher organic carbon (OC) (6.22 g kg^?1) and available N (188.5 kg ha^?1) compared to conventional tillage (CT) + recommended fertilizer (RF) + off-season tillage (OT) + hand weeding (HW) (OC: 4.71 g kg^?1, available nitrogen (N) (159.3 kg ha^?1). Among the physical soil quality parameters, mean weight diameter (MWD) was significantly higher under LT + 4 t ha^?1 straw + Hb (0.59 mm). The practice of LT + 4 t ha^?1 straw + HW recorded significantly higher microbial biomass carbon (MBC) (388.8 μg g^?1). The order of key indicators and their contribution towards soil quality was as follows: OC (29%) >, MBC (27%) > available zinc (Zn) (22%) > MWD (9%) > available boron (B) (8%), > dehydrogenase activity (DHA) (5%). The order of the best treatment which maintained soil quality index (SQI) values reasonably good (>1.5) was as follows: LT + 4t ha^?1 compost + HW (1.65) > LT + 4 t ha^?1 compost +Hb (1.60) > LT + 4t ha^?1 straw + HW (1.50). Hence, these treatments could be recommended to the farmers for maintaining higher soil quality in Vertisols under soybean system. Correlation studies revealed stronger relationship between key indicators like OC (R² = 0.627), MBC (R² = 0.884), available Zn (R² = 0.739) and DHA (R² = 0.604) with Relative Soil Quality Index (RSQI). The results of the present study would be highly useful to the researchers, farmers and land managers.     

A Comparative Study of Different Amendments on Amelioration of Saline-Sodic Soils Irrigated with Water Having Different EC: SAR Ratios

Soil degradation affects soil properties such as structure, water retention, porosity, electrical conductivity (EC), sodium adsorption ratio (SAR), and soil flora and fauna. This study was conducted to evaluate the response of contrasting textured soils irrigated with water having different EC:SAR ratios along with amendments: gypsum (G), farm manure (FM), and mulch (M). Water of different qualities viz. EC 0.6 + SAR 6, EC 1.0 + SAR 12, EC 2.0 + SAR 18, and EC 4.0 + SAR 30 was used in different textured soils with G at 100% soil gypsum requirement, FM at 10 Mg ha^?1, and M as wheat straw was added on surface soil at 10 Mg ha^?1. Results revealed that the applied amendments in soils significantly decreased pH_s and electrical conductivity (EC_e) of saturated paste and SAR. Four pore volumes of applied water with leaching fraction 0.75, 0.77, and 0.78 removed salts 3008, 4965, and 5048 kg ha^?1 in loamy sand, silty clay loam, and sandy clay loam soils, respectively. First four irrigations with LF of 0.82, 0.79, 0.75, and 0.71, removed 5682, 5000, 3967, and 2941 kg ha^?1 salts, respectively. The decreasing order for salt removal with amendments was FM > G > M > C with LF = 0.85, 0.84, 0.71, and 0.68, respectively. This study highlights a potential role of soil textures to initiate any mega program for reclamation of saline-sodic soils in the perspective of national development strategies.     

Effect of Municipal Solid Waste Compost and Farmyard Manure Application on Heavy‐Metal Uptake in Wheat

The risks related to municipal solid waste compost application in comparison to farmyard manure and mineral fertilizers on durum wheat were investigated on a short‐term experiment. Compost was applied at 40 t ha^?1 and 80 t ha^?1 with or without chemical fertilizers. Analogously, farmyard manure was applied at 40 t ha^?1. Both compost and farmyard manure improved plant growth and nutrient uptake. However, compost amendment showed more effectiveness, especially at 80 t ha^?1. Alternatively, this dose of compost involved an increase of plant copper, cadmium, and zinc concentrations in plant tissues. Metal accumulation did not thwart the enhancement of wheat yield. Furthermore, grain translocation factor reached 1 only in the case of copper; however, it showed a significant decrease following compost application (ranged between 0.57 and 0.69). Bioconcentration factor showed a significant decrease with municipal solid waste compost supply, constituting an internal detoxification mechanism.     

Effect of biochar and phosphorus fertilizer application on soil fertility: soil physical and chemical properties

This study evaluated the effect of biochar and phosphorus fertilizer application on selected soil physical and chemical properties in two contrasting soil types: Rhodic Ferralsols (clay) in Thohoyandou and Leptic Cambisols (loamy sand) in Nelspruit, South Africa. Field experiments were conducted in summer and winter. Treatments consisted of a factorial combination of four biochar levels (0, 5, 10 and 20 t ha^?1) and two phosphorus fertilizer levels (0 and 90 kg ha^?1) arranged in a randomized complete block design with three replicates. Chickpea was the test crop. Soil bulk density, aggregate stability, porosity, total C, total N, C:N ratio, K and Mg were determined. Biochar (10 t ha^?1) and phosphorus increased bulk density and decreased porosity at 0–5 and 15–20 cm soil depth on a loamy sand soil in both seasons. The interaction between biochar and phosphorus increased total C and total N on a clay soil in the summer sowing. However, in the loamy sand soil, biochar (10 t ha^?1) increased total C, C:N ratio, K and Mg in the summer sowing. The effect of biochar was more evident in the loamy sand soil than the clay soil suggesting that the influence of biochar may be soil-specific.     

Towards sustainable production of peppermint (Mentha piperita L.) through integrated use of vermicompost and cowpea green manuring with synthetic nitrogen fertilization

A field experiment with peppermint (Mentha piperita L.) was conducted in a sandy loam (Typic ustifluvent) soil during 2007 and 2008 at Lucknow, India. Ten treatments consisting of control (no synthetic or organic nitrogen fertilization), synthetic nitrogen fertilization (SN) 75, 150 and 225 kg ha^?1 alone, vermicompost (VC) 3 t + 37.5 kg SN ha^?1, VC 6 t + 75 kg SN ha^?1 and VC 9 t + 112.5 kg SN ha^?1 and intercropping of one, two and three rows of cowpea for green manuring in combination with 50, 100 and 150 kg SN ha^?1, respectively, were evaluated in a randomized block design. Integrated use of VC 9 t with 112.5 kg SN ha^?1 produced maximum essential oil (94.3 kg ha^?1), increased the herb and essential oil yields by 104 and 89%, respectively, over control and reduced SN use by 50%, without affecting the quality of essential oil. Application of VC and intercropping of cowpea for green manuring significantly improved the organic carbon, available N, P and K content in soil over SN alone. To get sustainable production of peppermint, application of VC 9 t ha^?1 along with 112.5 kg N ha^?1 through synthetic fertilizer is recommended for light textured sandy loam soils.     

Influence of organic amendments on dissipation kinetics of two different pesticides in soil: a case study

A study was undertaken to investigate the remedial effect of some soil amendments (farmyard manure (FYM), press mud compost (PMC), cereal straw (CS) at 5 t ha^?1 and fresh cow dung slurry (FCD) @ 0.5 t ha^?1) on dissipation kinetics of imidacloprid and sulfosulfuron under laboratory conditions. Incorporation of CS or FCD was found to be most effective in degrading both the pesticides at faster rates. Dissipation of both the pesticides could be well accounted by two component (1 + 1) first order kinetics. The computed values of parameters revealed that use of organic amendments increased the dissipated fraction of imidacloprid and sulfosulfuron. Incorporation of CS or FCD in soil maintained relatively higher dissipation rate constants for both faster and slower dissipation processes of pesticides in comparison to control. Hence, eco-friendly practices of CS or FCD incorporation as soil amendment in soil can play a vital role in preventing soil and water pollution.     

Tillage Effects on Particulate and Mineral‐Associated Organic Matter in Two Tropical Brazilian Soils

Abstract

Two Ferralsols (350 and 600 g kg^?1 clay) from the Brazilian Cerrado Region were evaluated for long‐term effects (5 and 8 years) of no tillage on carbon (C) stocks in particulate (>53 µm) and mineral‐associated (<53 µm) soil organic matter (SOM) fractions. Carbon stocks in particulate SOM increased under no tillage compared with conventional tillage, and the rate was higher in the clayey soil (0.62 Mg C ha^?1 yr^?1) than in the sandy clay loam soil (0.31 Mg C ha^?1 yr^?1). In contrast, the mineral‐associated SOM in the top soil layer (0–20 cm) was not affected by tillage system. Sequestration of atmospheric C in tropical no‐tillage soils seems to be due to accumulation of C in labile SOM fractions, with highest rates in clayey soils probably due to physical protection.     

The impact of different forest types on phytolith-occluded carbon accumulation in subtropical forest soils

Purpose

Occlusion of carbon in phytoliths is an important biogeochemical carbon sequestration mechanism and plays a significant role in the global biogeochemical carbon cycle and atmospheric carbon dioxide (CO₂) concentration regulation at a millennial scale. However, few studies have focused on the storage of phytolith and phytolith-occluded carbon (PhytOC) in subtropical forest soils.

Materials and methods

Soil profiles with 100-cm depth were sampled from subtropical bamboo forest, fir forest, and chestnut forest in China to investigate the variation of phytoliths and PhytOC storage in the soil profiles based on amass-balance assessment.

Results and discussion

The storage of phytoliths in the top 100 cm of the bamboo forest soil (198.13?±?25.08 t ha^?1) was much higher than that in the fir forest (146.76?±?4.53 t ha^?1) and chestnut forest (170.87?±?9.59 t ha^?1). Similarly, the storage of PhytOC in the bamboo forest soil (3.91?±?0.64 t ha^?1) was much higher than that in the fir forest soil (1.18?±?0.22 t ha^?1) and chestnut forest soil (2.67?±?0.23 t ha^?1). The PhytOC percentage in the soil organic carbon pool increased with soil depth and was the highest (4.29 %) in the bamboo forest soil. Our study demonstrated that PhytOC in soil was significantly influenced by forest type and the bamboo forest ecosystem contributed more significantly to phytolith carbon sequestration than other forest ecosystems.

Conclusions

Different forest types have a significant influence on the soil PhytOC storage. Optimization of bamboo afforestation/reforestation in future forest management plans may significantly enhance the biogeochemical carbon sink in the following centuries.

     

Nitrous oxide emissions from wetland soil amended with inorganic and organic fertilizers

Agricultural soils are a primary source of anthropogenic trace gas emissions, and the subtropics contribute greatly, particularly since 51% of world soils are in these climate zones. A field experiment was carried out in an ephemeral wetland in central Zimbabwe in order to determine the effect of cattle manure (1.36% N) and mineral N fertilizer (ammonium nitrate, 34.5% N) application on N₂O fluxes from soil. Combined applications of 0 kg N fertilizer + 0 Mg cattle manure ha^?1 (control), 100 kg N fertilizer + 15 Mg manure ha^?1 and 200 kg N fertilizer + 30 Mg manure ha^?1 constituted the three treatments arranged in a randomized complete block design with four replications. Tomato and rape crops were grown in rotation over a period of two seasons. Emissions of N₂O were sampled using the static chamber technique. Increasing N fertilizer and manure application rates from low to high rates increased the N₂O fluxes by 37–106%. When low and high rates were applied to the tomato and rape crops, 0.51%, 0.40%, and 0.93%, 0.64% of applied N was lost as N₂O, respectively. This implies that rape production has a greater N₂O emitting potential than the production of tomatoes in wetlands.     

Assessment of Environment-friendly Usage of Spent Wash and its Nutritional Potential for Sugarcane Production

Excessive and inappropriate use of fertilizers is a key factor of low sugarcane yield and degradation of soil. A two-year (2013–14 and 2014–15) field study was conducted to assess the impact of combined application of organic and inorganic fertilizers on sugarcane at research farm of Shakarganj Sugar Research Institute, Jhang, Pakistan. Experiment was conducted under randomized complete block design with three replications. Treatments were used as control (no exogenous application), spent wash (160 t ha^?1), (nitrogen, phosphorus and potassium) NPK (168:112:112 kg ha^?1), spent wash (120 t ha^?1) + NPK (42:28:28 kg ha^?1), spent wash (80 t ha^?1) + NPK (84:56:56 kg ha^?1), spent wash (40 t ha^?1) + NPK (126:84:84 kg ha^?1), and spent wash (160 t ha^?1) + NPK (42:28:28 kg ha^?1). Application of spent wash @ 80 t ha^?1 + NPK @ 84:56:56 kg ha^?1 resulted maximum crop growth rate (11.35 g m^?2 d^?1), leaf area index (7.78), and net assimilation rate (2.53 g m^?2 d^?1). Maximum number of millable canes (14), weight per stripped cane (0.90 kg), stripped cane yield (117.60 t ha^?1) and unstripped cane yield (141.25 t ha^?1) were observed with spent wash @ 80 t ha^?1 + NPK @ 84:56:56 kg ha^?1, followed by sole fertilizer application @ 168:112:112 kg NPK ha^?1 and spent wash @160 t ha^?1 + NPK @ 42:28:28 kg ha^?1. Similar trend was observed regarding quality parameters. The maximum benefit–cost ratio (1.80) was achieved with integrated application of spent wash @ 80 t ha^?1 + NPK @ 84:56:56 kg ha^?1.     

A glass house trial to investigate the impact of water treatment sludge and green waste compost to enhance the revegetation of contaminated sites

This study investigated the use of waste amendments (green waste compost (GWC) and water treatment sludge (WTS) cake) in improving the nutrient and revegetation status of contaminated soil obtained from a former industrial site that has heavy metal and hydrocarbon contamination. The waste amendments were mixed with the contaminated soil at application rates equivalent to 90 and 180 t ha^?1 (wet weight) and placed in plastic pots. The unamended soil serves as the control. Reed canary grass and white mustard were allowed to grow on the amended and unamended contaminated soil in the glass house. After a 30- day growth period, soil nutrient status was observed and was found to be higher in the amended contaminated soil than the control. In the amended soil, organic matter, total nitrogen, total potassium and soil nitrate were highest in contaminated soil amended with GWC at 180 t ha^?1 and lowest in contaminated soil amended with WTS cake at 90 t ha^?1. Above-ground dry mass of reed canary grass and white mustard grown on amended contaminated soil increased by 120–222% and 130–337%, respectively, as compared to the control, showing that improved fertility of contaminated soils thereafter, enhanced revegetation.     

Effect of Primary Biomethanated Spentwash on Soil Properties,Nutrient Uptake,and Yield of Wheat on Sodic Soil

The experiment on the effect of primary biomethanated spentwash (PBSW) on soil properties, nutrient uptake and yield of wheat on sodic soil was carried out at a research farm of Post Graduate Institute, Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra state, India, during the post-monsoon season. The experimental soil was sodic calcareous having Sawargaon series of isohyperthermic family of Vertic Haplustepts. The experiment was laid out in a randomized block design with nine treatments and three replications. The treatments consisted of varying doses of PBSW (100, 200, 300, 400 and 500 m³ ha^?1), absolute control, farmyard manure (FYM) 5 t ha^?1 + RDF-AST (recommended dose of fertilizer as per soil test), FYM 5 t ha^?1 + 50% GR (gypsum requirement) + RDF-AST and FYM 5 t ha^?1 + 100% GR + RDF-AST. The results revealed that the physical properties, namely bulk density and hydraulic conductivity, were improved in sodic soil due to the application of increased doses of PBSW. A significant reduction in pH, calcium carbonate and exchangeable sodium percentage (ESP) and an increase in organic carbon, cation-exchange capacity (CEC) and electrical conductivity (EC) were observed in the soil, due to the addition of PBSW. The available soil nitrogen (N), phosphorus (P), potassium (K) and micronutrient iron, manganese, copper and zinc (Fe, Mn, Cu and Zn) content after the harvest of wheat was the highest in the 500 m³ ha^?1 treatment compared with all the other treatments. The exchangeable calcium (Ca²⁺), magnesium (Mg²⁺) increased significantly and exchangeable Sodium (Na⁺) reduced significantly with increased doses of PBSW. The saturation paste extract analysis also showed the same trend. A significant increase in the EC of the saturation paste of extract of the soil was observed in all PBSW treatments and it was the highest (4.75 dS m^?1) in PBSW application @ 500 m³ ha^?1. The application of PBSW @ 500, 400, 300 and 200 m³ ha^?1 resembled the treatments of FYM + gypsum @ 100 GR + RDF-AST, FYM + gypsum @ 50 GR + RDF-AST and FYM + RDF-AST, respectively, regarding the biological properties of sodic soil. The PBSW application @ 500 m³ ha^?1 had recorded the highest grain (47.33 q ha^?1) and straw (72.72 q ha^?1) yield and the maximum total uptake of N, P, K, Fe, Mn, Cu, and Zn by wheat, which was at par with the treatment of FYM (5 t ha^?1) + gypsum @ 100% GR + RDF-AST.     

Effects of Goat Manure and Lime Addition on Phosphate Sorption by Two Soils from the Transkei Region,South Africa

More than 40% of soils in the Transkei region, South Africa, have high phosphorous (P) fixation capacities that necessitate application of high P fertilizer rates. This incubation study compared the effectiveness of goat manure (GM) and lime to minimize P sorption in two such soils. Manure application reduced P sorption in both soils, which was partly attributed to the liming effect of GM that resulted in marked reductions of exchangeable aluminum (Al). The liming effect of GM rates followed the order 20 t GM ha^?1 > 10 t GM ha^?1 > 5 t GM ha^?1. Therefore, GM can be cost‐effectively used to lime acid soils in the region and reduce their Al toxicity potential and P fertilizer requirements. Liming reduced P sorption on the Chevy Chase soil soon after application, but P sorption was reduced after 2 months on the Flagstaff soil, suggesting that the timing of liming for improved P availability could be critical for some soils.