Types of Irrigation Water and Soil Amendment Affect the Growth and Flowering of Petunia x alkinsiana ‘Bravo Pinc’

Water insufficiency is the hampering feature of crop sustainability,especially in arid and semi-arid regions.So,the effectual usage of all water resources especially underground brackish water represents the core priority in Saudi Arabia.The present study aimed to recognize the influence of different types of water irrigation(tap water as a control,salinized well water,and magnetized salinized well water)with or without soil amendments(soil without any amendment as a control,peat-moss,ferrous sulfate,and peat-moss plus ferrous sulfate)on petunia plant growth and flowering as well as ion content.Irrigating Petunia plants with saline well water adversely affected growth and flowering as compared to tap water and magnetized saline well water.Additionally,plants irrigated with magnetized water showed a significant enhancement in all the studied vegetative and flowering growth parameters as compared to those irrigated with salinized well water.Furthermore,mineral contents and survival of Petunia plants irrigated with magnetized well water were higher than those irrigated with tap water.Irrigation with magnetized well water significantly reduced levels of Na+and Cl−ions in leaves of Petunia plants indicating the role of magnetization in alleviating harmful effects of salinity.In conclusion,we recommend the utilization of magnetized saline well water for irrigating Petunia plants either alone or in combination with soil amendments(peat moss plus ferrous sulfate).

Heavy metal pollution risk of desulfurized steel slag as a soil amendment in cycling use of solid wastes

The by-product of wet flue gas desulfurization,desulfurized steel slag(DS),had chemical characteristics like natural gypsum that can be used to improve saline-sodic soil.However,contamination risk of heavy metals for cycling utilization of DS in agriculturewas concerned mostly.Both pot and field experiments were conducted for evaluating the potential pollution risk of DS as the amendment of saline-sodic soil.Results showed that application of DS decreased the contents of Cd,Cu,Zn,and Pb,while significantly increasing chromium(Cr)content in DS-amended soils.The field experiment demonstrated that the migration of heavy metals(Cd,Zn,Cu,and Pb)in the soil profile was negligible.The application of DS at the dosage of 22.5–225 tons/ha significantly increased the Cr content in alfalfa(Medicago sativa L.)but lower than the national standard for feed in China(GB 13078-2017).DS altered the chemical fraction of heavy metals(Zn,Cu,and Pb),transferred exchangeable,reducible into oxidizable and residual forms in DS-amended soil.Application of DS combined with fulvic acid(FA)could effectively reduce the movement of heavy metals in soil and the accumulation of Cr in alfalfa.Based on our results,DS was a safe and feasible material for agricultural use and presented relatively little pollution risk of heavy metals.However,the results also showed that DS to a certain extent had a potential environmental risk of Cr if larger dosages of DS were used.

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.

Effects of different soil amendments on physicochemical property of soda saline-alkali soil and crop yield in Northeast China

Soil amendment is one of the most effective methods to improve saline-alkali soil.In this study,laboratory experiments were conducted to verify the effect of 13 kinds of amendments and their combinations(Citric acid(NM),Phosphogypsum(LS),Aluminum sulfate+citric acid(AL+NM),Aluminum sulfate+phosphogypsum(AL+LS),Aluminum sulfate+citric acid+phosphogypsum(HH),Zeolite(Z),Acidified zeolite(ZH),Aluminum sulfate(AL),Aluminum sulfate+zeolite(AL+Z),Aluminum sulfate+acidified zeolite(AL+ZH),Poly Aluminum chloride(ALCL),Polyaluminium chloride+zeolite(ALCL+Z),Polyaluminium chloride+acidified zeolite(ALCL+ZH))on soil pH,metal cations content,exchangeable Na+,exchangeable sodium percentage(ESP)in the lab.And then the five most effective amendments(Z,ZH,AL,AL+Z,and AL+ZH)were chosen applying both in dry field(maize field)and paddy field to evaluate their improvement on soda saline-alkali soil and crop yield in the northeast Songnen Plain,China.The lab results showed that AL,AL+Z and AL+ZH treatments could significantly reduce the pH in soil solution and increase the content of metal cations.Z and ZH treatments could adsorb metal cations in soil.Both in dry and paddy fields,all five treatments could increase the soil saturated hydraulic conductivity(Ks),increased from 9.63 to 60.02 mm/d and 0.18 to 33.25 mm/d,respectively,of which the AL treatment was the best;all five treatments could reduce the content of exchangeable Na+in soil,and decrease by 38.62%-61.33%and 25.24%-71.53%,respectively,of which the AL+ZH treatment was the best;all treatments could reduce soil exchangeable sodium percentage,and decrease by 0.14-0.22 and 0.14-0.41,respectively,of which the AL+ZH treatment was the best;AL,AL+Z and AL+ZH treatments could improve soil organic matter content;all treatments could effectively improve the yield of crops,and increase 23.98%-60.75%and 52.51%-260.21%,respectively,of which the AL treatment was the best in dry field and the AL+ZH treatment was the best in paddy field.The effect of AL treatment was the best in dry field and AL+ZH treatment was the best in paddy field of soda saline-alkali soil.This study could provide instructive information for the chemical improvement and agricultural utilization of soda saline-alkali soils in the world.

Evaluation on Soil Improvement Effects of Organic Fertilization in Honey Peach Orchard in the Longquan Mountain

Combined application of organic fertilizer is an effective measure to improve the productivity and ecological effect of newly added soil.However,the effect of organic fertilizer application in newly added orchard soil is not clear.In this project,the soil of newly built peach orchard in the Longquan Mountain of Chengdu was applied with 45 t/hm 2 of organic fertilizer.After 9 months of planting 6 varieties of honey peach(Wanhujing,Baifeng,Zhongtao 13,Huangjinmitao 1,Zhongpan 101,Zhongpan 104),the locally well developed peach orchard was taken as the control.The physical and chemical properties of soil from four topography(top slope,middle slope,lower slope and flat land)of newly built peach orchard were analyzed,and the effect of organic fertilizer on soil was evaluated.The results showed that combined application of organic fertilizer had different effects on soils from orchards with different varieties of peach and from different terrain parts of the same peach variety.Specifically,it had the best effect on soil improvement in Baifeng(local variety),Zhongpan 101 and Zhongpan 104(introduced varieties).Meanwhile,the best effect of soil improvement was found on top slope.Cluster analysis divided newly built peach orchards,uncultivated soil,and locally well developed peach orchard into four groups,indicating that the selected amount of organic fertilizer application in this study has improved the soil of peach orchards to some extent,but it was still necessary to increase the application amount.It was better for 54 t/hm 2 amount of organic fertilization on the part of top and middle slope,and 60 t/hm 2 on the lower slope and flat land.The comprehensive ecological benefit assessment of organic fertilizer should be conducted based on long-term monitoring of peach orchard ecological environment,fruit tree growth,fruit yield and quality,which would provide scientific basis for peach orchard production and management.

Soil Moisture Retention on the High Plains of North America via Compost Amendments: A Longitudinal Field Study

Water is a finite but vital resource, and the volume of water used in arid and semi-arid regions must be managed to its fullest and best use. Irrigation water is approximately 37% of the total water used in the United States by volume annually. Thus, this area of water use is critical for local and national water conservation. Irrigation is primarily used to increase soil water content above that which precipitation can supply. Soil structure and associated effects on drainage and evapotranspiration, however, largely control soil water content, no matter the amount of applied water. Therefore, improving soil structure to hold more water decreases the amount of water needed for irrigation, which frees that water for other uses. In this paper, organic compost amendments are studied to determine the change in soil structure and accompanying improvements in soil water content over a 4-year period. A uniform field site was selected for this research in the high plains of South Dakota, where irrigation water was available for crop growth. The test site was divided into two equal area fields;one without compost and a field with compost amendments added to 20 cm depth. Compost was incorporated into the treated field at rates of 5% and 10% by weight. Both fields received the same tillage, seed, fertilizer, weather and irrigation. Weekly to monthly in-situ water content measurements from both fields were recorded at the surface and the depths of 20, 40 and 60 cm from 2017 to 2020. Precipitation and applied irrigation water were recorded at the site. No irrigation occurred in 2019 and 2020, and moisture content was dependent on natural precipitation in those years. Results of water content and soil structure show significant differences in the water contents of the soils with the compost amendments compared to baseline, with higher compost content resulting in higher water contents without the soil becoming over-saturated. These results were consistent at all depths and across all growing seasons. This work demonstrates the efficacy of compost soil amendments in regulating soil moisture, which has profound impacts on crop yields, topsoil erosion losses, carbon sequestration, and water conservation.

Facultative-anaerobic microbial digestion of coal preparation waste and use of effluent solids to enhance plant growth in a sandy soil

Coal preparation solid waste,which is a major environmental issue for coal-producing areas in China,may be microbiologically digested and transformed into a product suitable as a soil amendment to increase soil organic matter content and prevent and enhance plant/crop growth.Coal preparation waste collected from a coal sorting plant in Inner Mongolia,China was digested in bioreactors inoculated with microbial enrichments prepared from activated sludge and cow manure.The effluent solids from the coal preparation waste bioreactors were analyzed for their suitability as organic soil amendments,which complied with China standards.Plant growth tests were conducted in sandy soil from a semi-arid region in Colorado,which was amended with the effluent solids.Kentucky bluegrass(Poa pratensis L.)and chives(Allium schoenoprasum)were used as the representative plants for the growth tests,where results indicated substantially higher yields of Kentucky bluegrass and chives for the sandy soils amended with the effluent solids when compared to a commercial organic fertilizer.The number and average length of Kentucky bluegrass shoots were 10 and 5.1 times higher,respectively,in soils amended with the effluent solids.Similarly,the number and average length of chives shoots were 10 and 1.7 times higher,respectively,in soils amended with the effluent solids.Overall,the microbial digestion of coal preparation waste for application as an organic soil amendment is a viable alternative and beneficial use of coal preparation solid waste.

Soil inorganic amendments produce safe rice by reducing the transfer of Cd and increasing key amino acids in brown rice

The digestibility of cadmium(Cd)in brown rice is directly related to amino acid metabolism in rice and human health.In our field study,three kinds of alkaline calcium-rich soil inorganic amendments(SIAs)at three dosages were applied to produce safe rice and improve the quality of rice in Cd-contaminated paddy.With the increased application of SIA,Cd content in iron plaque on rice root significantly increased,the transfer of Cd from rice root to grain significantly decreased,and then Cd content in brown rice decreased synchronously.The vitro digestibility of Cd in brown rice was estimated by a physiologically based extraction test.Results showed that more than 70%of Cd in brown rice could be digested by simulated gastrointestinal juice.Based on the total and digestible Cd contents in brown rice to evaluate the health risk,the application of 2.25 ton SIA/ha could produce safe rice in acidic slightly Cd-contaminated paddy soils.The amino acids(AAs)in brown rice were determined by high-performance liquid chromatography.The contents of 5 key AAs(KAAs)that actively respond to environmental changes increased significantly with the increased application of SIA.The structural equation model indicated that KAAs could be affected by the Cd translocation capacity from rice root to grain,and consequently altered the ratio of indigestible Cd in brown rice.The formation of indigestible KAAs-Cd complexes by combining KAAs(phenylalanine,leucine,histidine,glutamine,and asparagine)with Cd in brown rice could be considered a potential mechanism for reducing the digestibility of Cd.

Biochar Production and Application in Forest Soils-A Critical Review

The increasing deforestation with an alarming rate is the prime cause of upsetting the balance in the natural ecosystem and the livelihood of local communities.Sustainable forest management and reforestation efforts can equilibrium this destruction and maintain the protected areas.In this regard,soil management strategies for reforestation of the degraded forest land can be helpful.In this review,the potential of using biochar,a solid carbon rich product of biomass thermochemical conversion,as a soil amendment in forest soils has been discussed.The production procedures of biochar,availability of feedstocks and the biochar properties are discussed using the existing knowledge.The positive effects of biochar are soil quality depended and change with varying geographical locations.Therefore,long-term field trials examining a range of biochars,soils,and forest types are required for a better understanding of this issue.Careful planning to match biochar with the soil properties is essential to obtain maximum benefits of biochar as a soil amendment.

Biochar as a Soil Ameliorant: How Biochar Properties Benefit Soil Fertility—A Review

In recent years, biochar has received great attention among researchers worldwide. This carbon-rich material, mainly produced from residues from agriculture and forestry, holds a wide range of properties, e.g. large specific surface area, high cation exchange capacity, and substantial nutrient contents, that can have beneficial effects when added to soils. This review is giving a brief introduction to biochar properties and how feedstock, pyrolysis temperature, and time influence these properties. As the majority of studies concentrate on the soil amending effects of biochar, this review also provides an overview of how biochar affects the chemical, physical, hydrological, and biological properties of soils. For example, biochar addition to soils can raise the pH, increase the organic carbon content, enhance nutrient retention, foster porosity, augment the water-holding capacity, and increase microbial biomass. Consequently, biochar can contribute to soil fertility, increase yields, help closing nutrient cycles, and thus help secure food safety in a region. However, the knowledge about the long-term effects is still limited and should be broadened by a more systematic testing of biochar effects in the future to help bring the benefits of biochar into practice.

Mitigating Cadmium (Cd) Toxicity in Montane Forest Soils Using Biochar: Laboratory Trial for Soils from Horton Plains, Sri Lanka

Horton Plains (HP), one of the two montane forests in Sri Lanka and habitat to many endemic species of plants and animals, has been severely affected by forest dieback. Past research has identified a direct link between soil pollution with Cadmium (Cd) and the phenomenon of forest dieback. As a consequence, forest dieback is increasing proportionately to the soil pollution. Hence, this study focuses on identifying a cost-effective remediation technique to neutralize soil Cd, and thereby reducing forest dieback. Soil samples were collected from HP, mainly Thotupolakanda site which shows more than 90% severity of forest die back, and bulked together. The soil was high (13.4) in organic matter and low (5.42) in pH, and three soil amendments were tested in this research as;bio char prepared using 1) rubber nut shells, 2) rice husk, and 3) dead wood from HP. Each sample was spiked with 20 ml of 5 ppm (parts per million) Cd solution, and four treatments a) soil + rubber-nut shell biochar (T1), b) soil + rice husk biochar (T2), c) soil + wood-from-HP biochar (T3), and d) soil only (T4), with five (05) replicates, were setup. During the first eight weeks after the application of treatments, it was observed that T1 showed the best performance, by showing a consistent trend in reducing the available soil Cd, with T2 following closely. The interesting observation was that the natural forest soil (T4) was also able to buffer the loading of Cd. At the close of the experiment, it was observed that the available soil Cd goes almost to zero, in less than 24 months.

Superabsorbent Polymer and Rabbit Manure Improve Soil Moisture, Growth and Yield of Eggplant (Solanum melongena L.)

Production of eggplant(Solanum melongena L.)is influenced by limited soil water and fertility conditions that affect its growth and yield.The use of superabsorbent polymer(SAP),also known as slush powder and rabbit manure are among the strategies that can improve soil conditions,hence growth and yield of crops.The objective of the study was to evaluate the effects of SAP and rabbit manure on soil moisture,growth and yield of eggplant.The study was conducted at Pwani University,Kilifi,Kenya.A randomized complete block design with three replications was used.The treatments were SAP,rabbit manure,SAP plus rabbit manure and control(without SAP or rabbit manure).Soil moisture,growth and yield parameters were determined.Superabsorbent polymer and/or rabbit manure improved soil moisture,growth and yield of eggplant compared with the control.Use of SAP had a better soil moisture retention,growth and yield comparable to SAP combined with rabbit manure.The finding demonstrates that use of SAP and/or rabbit manure may help in better soil water and nutrient management,particularly in arid and semi-arid areas to improve growth and yield of eggplant.

Chitin, Biochar, and Animal Manures Impact on Eggplant and Green Pepper Yield and Quality

The global obligation for food requires soil and plant management practices that provide valuable effects on the physical, chemical, and organic properties of soils. The use of animal manure, in agricultural production systems as alternative to synthetic elemental fertilizers has potential application to improve crop yield and fruit quality. A randomized complete block design (RCBD) was established to investigate the impact of nine soil treatments on yield and quality of bell pepper, Capsicum annuum and eggplant, Solanum melongena. The nine soil treatments included: chitin CH, biochar Bio, sewage sludge SS, chicken manure CM, SS mixed with biochar (SSBio), SS mixed with CH (SSCH), CM mixed with biochar (CMBio), CM mixed with CH (CMCH), and unamended (UN) native soil used as control treatment. At maturity, fruits from each treatment, were counted, weighed, and classified according to the USDA grades to U.S. Fancy, U.S. No.1, U.S. No.2, and culls. Overall number and weight of green pepper fruits collected from plants grown in SSCH were significantly greater (26.2 and 3.14 kg 5 plants-1) compared to fruits of plants grown in unamended control treatment (17.1 and 1.98 kg 5 Plants-1, respectively). Whereas CH alone was superior in increasing the number and weight of eggplant fruits compared to the control treatment. Average weight and number of eggplant fruits of plants grown in soil amended with chitin (4.46 kg and 11.5, respectively) were significantly (P ≤ 0.05) greater than weight and number of fruits obtained from plants grown in other soil treatments. Results also revealed a positive correlation coefficient (r) and high probability of significance (P) between number of fruits and weight of fruits among the nine soil treatments. Utilization of animal manures in agricultural systems is an inexpensive means for limited-resource farmers looking for improvements in crop yield and quality at affordable costs.

Application of Rice Husk Biochar for Achieving Sustainable Agriculture and Environment

This paper critically reviewed the current knowledge and challenges of rice husk biochar(RHB)production and its effects on soil properties,plant growth,immobilization of heavy metals,reduction of nutrient leaching and mitigation of greenhouse gas emissions.The characteristics of RHBs produced at various pyrolysis temperatures were discussed and compared to biochars derived from other agro-industrial wastes.RHBs produced at higher pyrolysis temperatures show lower hydrogen/carbon ratio,which suggests the presence of higher aromatic carbon compounds.The increase of pyrolysis temperature also results in production of RHBs with higher ash content,lower yield and higher surface area.RHB usually has higher silicon and ash contents and lower carbon content compared to biochars derived from other feedstocks at the same pyrolysis conditions.Although it depends on soil type,RHB application can improve soil organic carbon content,cation exchange capacity,available K concentration,bulk density and microbial activity.The effect of RHB on soil aggregation mainly depends on soil texture.The growth of different crops is also enhanced by application of RHB.RHB addition to soil can immobilize heavy metals and herbicides and reduce their bioavailability.RHB application shows a significant capacity in reduction of nitrate leaching,although its magnitude depends on the biochar application rate and soil biogeochemical characteristics.Use of RHB,especially in paddy fields,shows a promising mitigation effect on greenhouse gas(CH4,CO2 and N2O)emissions.Although RHB characteristics are also related to other factors such as pyrolysis heating rate and residence time,its performance for specific applications(e.g.carbon sequestration,pH amendment)can be manipulated by adjusting the pyrolysis temperature.More research is needed on long-term field applications of RHB to fully understand the advantages and disadvantages of RHB as a soil amendment.

Sugarcane bagasse amendment mitigates nutrient leaching from a mineral soil under tropical conditions

Large quantities of organic by-products are generated by the sugarcane industry during sugar extraction process.These by-products may be used as soil amendments to improve soil quality,as nutrient leaching is common in mineral soils of Florida in USA due to their sandy texture and frequent rain events.A soil column study was designed to evaluate the effects of bagasse application at 85 t ha^(-1) of fresh bagasse,170 t ha^(-1) of fresh bagasse,and 170 t ha^(-1) of fresh bagasse+nitrogen(N)on the leaching potential of carbon(C),N,phosphorus(P),and potassium(K).Bagasse was incorporated within the topsoil(0-15 cm)in outdoor soil columns exposed to natural conditions,with periodical irrigation during the experiment.After approximately 57 weeks,the distributions of C,N,P,and K were evaluated at three soil depths(i.e.,0-15,15-30,and 30-53 cm)within the soil columns.Total organic C(TOC),N,and P in leachates decreased significantly from the soils amended with bagasse compared with the control with no bagasse and no N.Based on K content changes in the columns,bagasse could also be utilized as a potential source of K for plants.Overall,application of bagasse as a soil amendment might be an effective way to sustainably reutilize organic by-products while reducing concerns regarding major nutrients entering groundwater resources.The results of this study could assist in developing nutrient management plans of using sugarcane bagasse as a potential soil amendment in mineral soils.

Potential of biochar and organic amendments for reclamation of coastal acidic-salt affected soil

Salinity and acidity have affected several hundred million hectares of land throughout the globe which poses a major threat to global food security and biodiversity.Application of organic amendments for salt-affected soils has been identified as one of the most effective ways to mitigate salinity-induced problems and considered as a green technique offering twin benefits of waste load reduction and land reclamation.However,studies on reclaiming acidic-salt affected soils are limited.Therefore,this study aimed to determine the reclamation potential of biochars and organic amendments involving Gliricidia sepium biochar produced at 300℃,500℃,and 700℃,green waste compost,and municipal sewage sludge at three different amend-ment ratios,1.0%,2.5%and 5.0%.The incubation experiment was conducted for a 4-month period with different amendment ratios applied to the coastal acidic-salt affected soil.Subsamples were extracted from incubation pots after 1 and 4 months and analyzed for soil chemical parameters(pH,EC,NO_(3)^(−),PO_(4)^(3−,total organic carbon,cation exchange capacity,sodium adsorption ratio,exchangeable sodium percentage)and microbial enzyme activity(catalase activity,and acid-and alkaline phosphatase activity).All organic amendments demonstrated enhancement of the soil properties in a significant manner.However,increasing incubation time and amendment ratio increase the changes of soil parameters by a great percentage.Therefore,the maximum amendment ratio of 5.0%and 4 months of incubation period rendered a significant improvement in the reclamation of acidic-salt affected soil.However,the biochar produced at 500℃ contributed the maximum towards the improved physicochemical and biochemical profile of acidic-salt affected soil,making it the most promising organic amend-ment for the reclamation of acidic-salt affected soil.The overall reclamation efficiency of organic amendments registered the following order of variation:700 BC<Sludge<300 BC<Compost<500 BC.

Interactive effects of deficit irrigation and vermicompost on yield,quality,and irrigation water use efficiency of greenhouse cucumber

Water scarcity is the most significant barrier to agricultural development in arid and semi-arid regions.Deficit irrigation is an effective solution for managing agricultural water in these regions.The use of additives such as vermicompost(VC)to improve soil characteristics and increase yield is a popular practice.Despite this,there is still a lack of understanding of the interaction between irrigation water and VC on various crops.This study aimed to investigate the interaction effect of irrigation water and VC on greenhouse cucumber yield,yield components,quality,and irrigation water use efficiency(IWUE).The trials were done in a split-plot design in three replicates in a semi-arid region of southeastern Iran in 2018 and 2019.Three levels of VC in the experiments,i.e.,10(V_(1)),15(V_(2)),and 20 t/hm^(2)(V_(3)),and three levels of irrigation water,i.e.,50%(I_(1)),75%(I_(2)),and 100%(I_(3))of crop water requirement were used.The results showed that the amount of irrigation water,VC,and their interaction significantly affected cucumber yield,yield components,quality,and IWUE in both years.Reducing the amount of irrigation water and VC application rates reduced the weight,diameter,length,and cucumber yield.The maximum yield(175 t/hm^(2))was recorded in full irrigation using 20 t/hm^(2)of VC,while the minimum yield(98 t/hm^(2))was found in I_(1)V_(1)treatment.The maximum and minimum values of IWUE were recorded for I_(1)V_(3)and I_(3)V_(1)treatments as 36.07 and 19.93 kg/(m^(3)•hm^(2)),respectively.Moreover,reducing irrigation amount decreased chlorophyll a and b,but increased vitamin C.However,the maximum carbohydrate and protein contents were obtained in mild water-stressed conditions(I_(2)).Although adding VC positively influenced the value of quality traits,no significant difference was observed between V_(2)and V_(3)treatments.Based on the results,adding VC under full irrigation conditions leads to enhanced yield and IWUE.However,in the case of applying deficit irrigation,adding VC up to a certain level(15 t/hm^(2))increases yield and IWUE,after which the yield begins to decline.Because of the salinity of VC,using a suitable amount of it is a key point to maximize IWUE and yield when applying a deficit irrigation regime.

Role of organic amendments in reducing leaching of sulfosulfuron through wheat crop cultivated soil

A field study with wheat crop was undertaken to examine the efficacy of two soil amendments,cereal straw and fresh cow dung slurry,in reducing leaching of sulfosulfuron to groundwater and its residue load in soil.The herbicide was extracted by the QuEChER’S method and quantified through high performance liquid chromatography.The amendments had no effect on the general properties of groundwater.Both cereal straw and fresh cow dung reduced leaching of sulfosulfuron into groundwater but cereal straw was more effective,probably because its addition decreases soil pH,thereby causing faster hydrolysis of the herbicide.At harvest time,residues of the herbicide in grains,straw and soil were below recommended maximum residue limits(0.1mg kg-1)with both amendments.Thus,both the amendments can be recommended for wheat cropping systems to control sulfosulfuron leaching to groundwater.

Structural and chemical changes in pyrogenic organic matter aged in a boreal forest soil

Pyrogenic organic matter(PyOM)is formed during wildfires and prescribed burnings or produced intentionally in the form of biochar for soil amendment purposes.It is attracting a growing scientific and practical interest due to its important role in the global carbon cycle and agronomic applications as a soil enhancer.Most of the studies on the physicochemical properties of PyOM have been conducted using fresh biochars even though the characteristics of PyOM are expected to alter due to aging processes in soil environment.In this paper,we report the results of a study that utilized X-ray microtomography and elemental analysis to investigate the chemical and structural changes in the PyOM formed during prescribed burning events and aged thereafter for 1–71 years in a boreal forest soil.Our results indicate that changes in elemental composition occurred at decadal timescales,and an apparent steady state was reached ca.30 years after PyOM formation and exposure to the environment.At such timescales,PyOM was able to retain its porous structure originating from the cellular structure of the initial wood tissues.However,structural analysis revealed several effects of aging on the pore structure,such as the formation of surface coating layers,pore fillings,and fractures.These changes may alter pore size distribution and accessibility of the pores and further alter the influence of PyOM on soil functions,such as the transfer and retention of water and nutrients in PyOM pores.

Influence of pyrolysis temperature on rice straw biochar properties and corresponding effects on dynamic changes in bispyribac-sodium adsorption and leaching behavior in soil

Bispyribac-sodium is a weakly acidic herbicide with high water solubility and is thus a potential source of groundwater contamination.Considering the risk inherent to the use of this herbicide,this study assessed the impacts of rice straw(RS)and biochar amendments on the adsorption and leaching behavior of bispyribac-sodium in soil.Biochars were produced from RS at different pyrolysis temperatures and characterized using various spectral techniques.Rice straw had a surface area of 3.996×10^(4)m^(2)kg^(-1),which increased under pyrolysis;biochars prepared at 350 and 550℃(RS350 and RS550)in a closed furnace with limited oxygen supply had a surface area of 5.763×10^(4)and 6.890×10^(4)m^(2)kg^(-1),respectively,and biochar prepared by purging the pyroformer with N2(RSC)had the highest surface area of 12.173×10^(4)m^(2)kg^(-1).After amendment with RS and biochar,soil Freundlich adsorption capacity(KF ads)increased to varying extents in the order RSC>RS350>RS550,from 2.89×10^(3)to 29.57×10^(3)mg^(1-1)/nkg^(-1)L1/n,compared to1.55×10^(3)mg^(1-1)/nkg^(-1)L1/nin unamended soil.The variability in KF ads of bispyribac-sodium amongst the RS-and biochar-amended soils was dependent on the surface area of the amendments.The desorption of bispyribac-sodium decreased in the RS-and biochar-amended soils and varied from90.45%to 95.20%in unamended soils and from 60.95%to 89.50%in amended soils.The adsorption and desorption of bispyribac-sodium varied significantly depending on its concentration and the type and application rate of soil amendment.Different leaching risk evaluation indices,viz.,modified leach index(M.LEACH),leach index(LEACH),groundwater ubiquity score(GUS),Hornsby index(HI),leaching index(LIN),and pesticide leaching potential(PLP)index,were used to assess the susceptibility of groundwater to herbicide leaching.To reduce the repetitive effects of common parameters in each index,a new index was developed by employing principal component analysis(PCA)to condense their information into a single ranking.The results of the PCA indicated that RS and biochar amendments could be an effective management practice for controlling the leaching potential of bispyribac-sodium in soil.