Availability of iron,manganese, zinc and phosphorus in submerged sodic soil as affected by amendments during the growth period of rice crop

Summary Effect of amendments, gypsum (12.5 tonnes/ha), farmyard manure (30 tonnes/ha), rice husk (30 tonnes/ha) and also no amendment (control) on the availability of native Fe, Mn and P and applied Zn in a highly sodic soil during the growth period of rice crop under submerged conditions was studied in a field experiment. Soil samples were collected at 0, 30, 60 and 90 days of crop growth. Results showed that extractable Fe (1N NH₄OAC pH 3) and Mn (1N NH₄OAC pH 7) increased with submergence upto 60 days of crop growth but thereafter remained either constant or declined slightly. Application of farmyard manure and rice husk resulted in marked improvement of these elements over gypsum and control. Increases in extractable Mn (water soluble plus exchangeable) as a result of submergence and crop growth under different amendments were accompanied by corresponding decreases in easily reducible Mn content of the soil. Application of 40 kg zinc sulphate per hectare to rice crop could substantially raise the available Zn status (DTPA extractable) of the soil in gypsum and farmyard manure treated plots while the increase was only marginal in rice husk and control plots indicating greater fixation of applied Zn. Available P (0.5M NaHCO₃ pH 8.5) behaved quite differently and decreased in the following order with crop growth: gypsum>rice husk>farmyard manure>control.     

Diary

Abstract

The use of organic amendments is a common practice in Pakistan to improve soil fertility. Organic amendments affect the chemical speciation and thus the bioavailability of heavy metals and their uptake and toxicity to plants. The present study evaluates the influence of organic amendments viz. farm yard manure (FM), poultry manure (PM), press mud (PrM) and activated carbon (AC) on nickel (Ni) bioavailability in soil, as well as its uptake into, and growth responses of, Trifolium alexandrinum. Pot experiments were conducted where T. alexandrinum was exposed to three different concentrations of Ni i.e., 30, 60 and 90 mg kg^?1 in the form of NiCl₂ solution in the presence and absence of organic amendments each applied at 15 g kg^?1 soil. The results showed that the effect of organic amendments on Ni bioavailability and uptake by T. alexandrinum depended on the Ni concentration in the soil and the amendment type. Application of organic amendments generally increased Ni phytoavailability in soil and Ni uptake by plants at low Ni levels (Ni-0 and Ni-30) but decreased at higher levels (Ni-60 and Ni-90).     

Comparison of Chicken Manure and Urea Fertilizers as Potential Soil Amendments for Enhanced Phytoextraction of Heavy Metals

Cadmium (Cd) solubilization in soil and uptake by Mucuna pruriens var. pruriens and Sphenostylis stenocarpa was studied in response to the chicken manure and urea fertilizers application types. In this study, 0.8 g each of the amendments was applied to petroleum-contaminated soil in a pot experiment. Results indicate that the chicken manure application at 14 days before planting gave significantly higher shoot dry matter than its urea counterpart under conditions of Cd stress. Chicken manure application resulted in less Cd solubilization as compared with urea fertilizer dosing. The chicken manure application also significantly increased the shoot Cd accumulation despite its lesser effect on Cd solubilization; thus, it is expected to minimize the risk of groundwater contamination. Chicken manure amended treatment showed greater Cd tolerance for the two species investigated and S. stenocarpa did not support Cd phytoextraction. Although the amendments gave marked reduction in Cd phtotoxicity, those of the urea fertilizer gave only rapid, but short, growth support.     

Use of composts to manage corky root disease in organic tomato production

Corky root disease of tomato caused by Pyrenochaeta lycopersici is an economically important disease in organic tomato production. This study aimed to evaluate the effects of various composts consisting of green manure, garden waste and horse manure against corky root disease through bioassay under greenhouse conditions, where soil naturally infested with P. lycopersici was used as a root substrate. The various composts were mixed at a rate of 20% (v/v) with the infested soil. Disease severity (measured as infected roots) in the unamended soil was compared with that in the soil–compost mixtures. One of the composts made from garden waste significantly reduced the disease, whereas horse manure compost significantly stimulated it. Lower concentrations of NH₄‐N and total carbon and a higher concentration of Ca in the substrate were correlated with lower level of corky root disease. Addition of green manure or garden waste compost to the infested soil increased total microbial activity or population density of copiotrophic bacteria and actinomycetes, respectively. However, increased microbial activity or microbial population in soil–compost mixtures was not associated with a reduction in corky root disease severity in the present study.     

Use of Vetiver and Three Other Grasses for Revegetation of Pb/Zn Mine Tailings: Field Experiment

The Lechang Pb/Zn mine is located to the north of the Guangdong Province, South of China. The tailings pond had been abandoned for over 5 years, and revegetation was necessary for stabilizing the bare surface and to reduce its environmental impact. The tailings contained high levels of heavy metals (Pb, Zn, Cu, and Cd) and low levels of major nutrient elements (N, P, and K) and organic matter; therefore, heavy metal toxicity and extreme infertility were the major constraints on revegetation. A field experiment was conducted to compare the growth of Vertiveria zizanioides, Paspalum notatum, Cynodon dactylon, and Imperata cylindrica var. major on the tailings. The tailings were amended with 10 cm domestic refuse + complex fertilizer (NPK) (Treatment A), 10 cm domestic refuse (Treatment B) and complex fertilizer (NPK) (Treatment C), respectively; tailings without any amendment were used as control (Treatment D). Plant growth was improved when either domestic refuse or NPK fertilizer was added to the substrate, but the combination of both amendments gave the best yields. After 6 months' growth, V. zizanioides growing on treatment A had a height of 220 cm, cover of 100% and a yield of 2.1 kg m^-2 (d.w.). The height and biomass of V. zizanioides were significantly greater than the other three grasses growing on the same treatment. Judging from results, V. zizanioides was the best species for tailings revegetation, followed by P. notatum, C. dactylon, and I. cylindrica var. major.     

Improving the growth of Ni-hyperaccumulating plants in serpentine quarry tailings

Phytomining techniques based on metal-hyperaccumulating plants can be implemented in serpentine quarry wastes for Ni recovery. However, strategies must be developed to overcome the unfavourable plant growth conditions that these substrates present and to optimize Ni yields. In this study, the Ni hyperaccumulators Alyssum serpyllifolium, Alyssum inflatum, and Alyssum bracteatum were evaluated for their Ni phytoextraction efficiency from quarry tailings. Effects of two organic amendments, composted municipal sewage sludge and cow manure, on plant growth and physiological status and Ni removal were determined. Organic amendments were incorporated at two addition rates (5% and 20% w/w). The best-performing hyperaccumulators were A. inflatum and A. serpyllifolium. Organic amendments improved plant biomass production, photosynthetic efficiency and nutrition, but reduced shoot Ni concentrations. However, the stimulation in biomass resulted in significantly enhanced Ni yields. The most promising results were found using low addition rates and after manure incorporation.     

Effect of organic amendments on seedling infection of rice caused byRhizoctonia solani

Summary Soils amended with organic amendments such as rice chaff, mustard cake, neem cake, saw dust and farm yard manure significantly reduced the seedling infection of rice owing toRhizoctonia solani. Significant increase in shoot growth was noticed in soils amended with organic amendments while reduction in root growth of rice seedlings was also observed owing to the addition of organic amendments such as sunflower cake, mustard cake, coconut cake and farmyard manure.     

Hibernacula selection by Townsend's big-Eared bat in southwestern Colorado

In western United States, both mine reclamations and renewed mining at previously abandoned mines have increased substantially in the last decade. This increased activity may adversely impact bats that use these mines for roosting. Townsend's big-eared bat (Corynorhinus townsendii) is a species of conservation concern that may be impacted by ongoing mine reclamation and renewed mineral extraction. To help inform wildlife management decisions related to bat use of abandoned mine sites, we used logistic regression, Akaike's information criterion, and multi-model inference to investigate hibernacula use by Townsend's big-eared bats using 9 years of data from surveys inside abandoned mines in southwestern Colorado. Townsend's big-eared bats were found in 38 of 133 mines surveyed (29%), and occupied mines averaged 2.6 individuals per mine. The model explaining the most variability in our data included number of openings and portal temperature at abandoned mines. In southwestern Colorado, we found that abandoned mine sites with more than one opening and portal temperatures near 0°C were more likely to contain hibernating Townsend's big-eared bats. However, mines with only one opening and portal temperatures of ≥10°C were occasionally occupied by Townsend's big-eared bat. Understanding mine use by Townsend's big-eared bat can help guide decisions regarding allocation of resources and placement of bat-compatible closures at mine sites scheduled for reclamation. When feasible we believe that surveys should be conducted inside all abandoned mines in a reclamation project at least once during winter prior to making closure and reclamation recommendations. © 2010 The Wildlife Society.     

种植香根草对铜尾矿废弃地基质化学和生物学性质的影响

通过实地调查取样和室内分析,研究铜陵水木冲铜尾矿废弃地不同时期种植香根草(Vetiveria zizanioides L.)群落(近期种植香根草群落(V.zizanioides communities were established in the recent stage,JX),中期种植香根草群落(V.zizanioides communities were established in the middle stage,ZX)和早期种植香根草群落(V.zizanioides communities were established in the early stage,OX))对尾矿基质化学性质、微生物量和土壤酶活性的影响,探讨人工植被恢复对铜尾矿废弃地基质系统的修复作用。结果表明:香根草的定植能延缓铜尾矿的酸化过程,且随着香根草定植时间的延长,0—5 cm和5—20 cm层尾矿基质中总氮和速效磷含量提高(其中,0—5 cm层总氮积累更加显著),OX下0—5 cm表层基质总氮和速效磷的平均值分别是JX下的4.64倍和22.44倍。基质微生物量C、N含量和脱氢酶、过氧化氢酶、脲酶活性也随香根草种植时间的延长而有不同程度的升高,且基质化学性质对微生物量和酶活性有影响,其中基质微生物量C、N含量、脱氢酶和过氧化氢酶活性均与电导率呈显著或极显著负相关性;而基质微生物量N和4种酶活性均与总氮含量呈显著或极显著正相关性,表明总氮含量是影响基质微生物量N和酶活性的主要因子;基质微生物量N、脱氢酶和过氧化氢酶活性还与速效磷含量呈极显著正相关性。基质中Cu、Pb含量对脱氢酶、过氧化氢酶活性和微生物量均有显著抑制作用,而Zn对基质微生物活性有一定的激活作用。生长在尾矿废弃地上的香根草不仅显著地改善了铜尾矿废弃地的基质化学性质,且有利于基质微生物量和酶活性的增加,是一种良好的矿业废弃地生态修复物种。     

Studies on the ecology of actinomycetes in an agricultural soil amended with organic residues: II. Assessment of enzymatic activities of <Emphasis Type="Italic">Actinomycetales</Emphasis> isolates

The main objective of this investigation was to study the enzymatic activities of Actinomycetales strains isolated from an agricultural soil amended with different amounts of municipal solid waste compost (MSWC) or farmyard manure (FM). For this purpose, the hydrolytic activities of carboxymethyl cellulase, xylanase, pectinase, amylase, chitinase and protease were tested for 75 isolates of Sterptomyces, Amycolatopsis and Nocardioides from different sources (unamended soil, amended soil with FM or MSWC, FM and MSWC) at temperature ranging between 30 and 50°C. It was shown that the highest rate of enzymes producer’s strains was registered at 30°C, and decreased gradually to annul at 50°C, with the exception of the MSWC strains origin. It was also shown that the percentage of strains producers of enzymes isolated from soil amended with MSWC appeared higher than the one registered for those isolated from control and amended with FM soils. Application of MSWC increases the number of enzymes producer-actinomycetes in the soil and then it improves its fertility.     

A Lifecycle Model to Evaluate Carbon Sequestration Potential and Greenhouse Gas Dynamics of Managed Grasslands

Soil amendments can increase net primary productivity (NPP) and soil carbon (C) sequestration in grasslands, but the net greenhouse gas fluxes of amendments such as manure, compost, and inorganic fertilizers remain unclear. To evaluate opportunities for climate change mitigation through soil amendment applications, we designed a field-scale model that quantifies greenhouse gas emissions (CO₂, CH₄, and N₂O) from the production, application, and ecosystem response of soil amendments. Using this model, we developed a set of case studies for grazed annual grasslands in California. Sensitivity tests were performed to explore the impacts of model variables and management options. We conducted Monte Carlo simulations to provide estimates of the potential error associated with variables where literature data were sparse or spanned wide ranges. In the base case scenario, application of manure slurries led to net emissions of 14 Mg CO₂e ha^?1 over a 3-year period. Inorganic N fertilizer resulted in lower greenhouse gas emissions than the manure (3 Mg CO₂e ha^?1), assuming equal rates of N addition and NPP response. In contrast, composted manure and plant waste led to large offsets that exceeded emissions, saving 23 Mg CO₂e ha^?1 over 3 years. The diversion of both feedstock materials from traditional high-emission waste management practices was the largest source of the offsets; secondary benefits were also achieved, including increased plant productivity, soil C sequestration, and reduced need for commercial feeds. The greenhouse gas saving rates suggest that compost amendments could result in significant offsets to greenhouse gas emissions, amounting to over 28 MMg CO₂e when scaled to 5% of California rangelands. We found that the model was highly sensitive to manure and landfill management factors and less dependent on C sequestration, NPP, and soil greenhouse gas effluxes. The Monte Carlo analyses indicated that compost application to grasslands is likely to lead to net greenhouse gas offsets across a broad range of potential environmental and management conditions. We conclude that applications of composted organic matter to grasslands can contribute to climate change mitigation while sustaining productive lands and reducing waste loads.     

Effect of Organic Amendments on the Oxygen Uptake of Pseudomonas putida—PAPs-1 in Chromium-Contaminated Pond Ash

In this study a Cr (VI) resistant bacterium Pseudomonas putida was isolated from pond ash and its oxygen consumption potential at different concentrations of Cr (VI) viz., 0, 100 and 200 mg kg^?1 was studied using Electrolytic Respirometry. Oxygen consumption by the bacterium was noticed up to 200 mg kg^?1 Cr (VI) concentration. To the pond ash (inoculated with and without Pseudomonas) 200 mg kg^?1 Cr (VI) was added and incorporated with different organic amendments such as farmyard manure (FYM), coir pith, paddy straw and press mud and the cumulative oxygen consumption was studied. The cumulative oxygen consumption by the bacterium was higher when the pond ash was incorporated with organic amendments. The highest oxygen consumption of 205 mg l^?1 was observed when press mud was used, which was followed by FYM (198 mg l^{? 1} ). Furthermore, the enrichment with press mud increased the nutrient content of N (57.28 mg kg^?1 ), P (5.5 mg kg^?1 ) and K (42.7 mg kg^?1 ) of the pond ash. The maximum dehydrogenase enzyme activity of 0.63 μ g TPF formed g^?1 sample h^?1 was measured when the pond ash was inoculated with Pseudomonas and enriched with press mud. The results also indicated that maximum reduction of Cr (VI) (42.5%) was observed when Pseudomonas and press mud were used. This study evaluated the possibilities of toxicity reduction and nutrient enrichment of the ash pond using a Cr (VI) resistant bacterium and organic amendments.     

Effects of Chicken-excrement Amendments on Meloidogyne arenaria

The effects of chicken litter on Meloidogyne arenaria in tomato plants cv. Rutgers were determined in the greenhouse. Tomato seedlings were transplanted into a sandy soil amended with five rates of chicken litter and inoculated with 2,000 M. arenaria eggs. After 10 days, total numbers of nematodes in the roots decreased with increasing rates of chicken litter. After 46 days, egg numbers also decreased with increasing litter rates. In another experiment, soil was amended with two litter types, N-P-K fertilizer, and the two primary constituents of chicken litter (manure and pine-shaving bedding). After 10 days, numbers of nematodes in roots were smaller in chicken-excrement treatments as compared to nonexcrement treatments. At 46 days, there were fewer nematode eggs in chicken-excrement treatments compared to nonexcrement treatments. Egg numbers also were smaller for fertilizer and pine-shaving amendments as compared to nonamended controls. Chicken litter and manure amendments suppressed plant growth by 10 days after inoculation but enhanced root weights at 46 days after inoculation. Amendment of soil with chicken litter suppressed M. arenaria and may provide practical control of root-knot nematodes as part of an integrated management system.     

Effects of organic amendments to soil on the rhizosphere microflora of antirrhinum infected withVerticillium dahliae Kleb.

Summary Organic (e.g. chitin, green manure, cellulose) amendments to soil induced quantitative and qualitative changes in the rhizosphere microflora of antirrhinum plants infected withVerticillium dahliae Kleb. Whereas reduction in disease severity occurred with chitin and green manure amendments, an increase in disease severity was observed with the application of cellulose. The reduction of the disease severity with chitin and green manure may be correlated with the increased population of actinomycetes in the antirrhinum rhizosphere.     

Studies on the ecology of actinomycetes in an agricultural soil amended with organic residues: I. identification of the dominant groups of <Emphasis Type="Italic">Actinomycetales</Emphasis>

The main objective of this investigation was to study the Actinomycetales community in a Tunisian agricultural soil amended with different amounts of municipal solid waste compost (MSWC) or farmyard manure (FM). It was shown, by using the 16S rDNA polymerase chain reaction—restriction fragment length polymorphism and sequencing methods for Actinomycetales isolates, tow major clusters. The cluster SI is composed of tow related families: Streptomycetaceae, dominant family and Pseudonocardiaceae. However, SII is composed of Nocardioidaceae family. The application of FM or MSWC increases the Actinomycetales number and affects their diversity by inhibition, stimulation or contribution of some species in soil. It was also shown, by the application of molecular techniques to soil samples using selective primers, that these three groups of Actinomycetales remain dominant even after 5 years of organic amendment application in soil.     

Soil pollution through industrial effluent and its management

During the survey of sewer water/industrial effluent composition, we identified a site at Sonepat that had turned barren due to excessive irrigation with cycle industry effluent. To study the ameliorative effect of farmyard manure, the bulk surface soil sample was brought from the site. Soil was amended with five levels of farmyard manure (0, 0.25, 0.5, 1.0, and 2.0% on a soil weight basis), and carrot, fenugreek, spinach, and wheat crops were grown as test crops in a screen house. The deleterious effect of excessive heavy metals, particularly Ni, on the yield of all the crops was reduced with the application of 2% farmyard manure. The Ni content was highest in carrot, followed by spinach, fenugreek, and wheat. With the application of 2% farmyard manure, Ni content was reduced from 434 to 267 mg/kg in carrot, 167 to 100 mg/kg in fenugreek, 300 to 166 mg/kg in spinach, and 65 to 42 mg/kg in wheat grain.     

Reclamation of abandoned magnesite site using amendments and plantation

This study aimed to determine the suitable reclamation ways of post-mining magnesite. It was hypothesized that adding amendments and planting would decrease pH, increasing the nutrient availability and enhancing the soil microbial activity. Treatments included 200 g gypsum, 2 kg goat manure, and 200 g sulfur per square meter. Cedar (Cedrus libani A. Rich.), black locust (Robinia pseudoacacia L.), black pine (Pinus nigra J.F. Arnold), and sainfoin (Onobrychis sativa L.) were planted. Before and after the treatments, samples were taken from each experimental unit and analyzed. Analysis of the data indicated that the pH had decreased by 0.6 and 0.5 units on the gypsum + sulfur- and gypsum + manure-treated experimental units, respectively, compared to the other treated plots. In addition, using manure significantly increased the organic matter N, P, and K content, by 3-fold, 2.5-fold, 7.5-fold, and 2.5-fold, respectively, and enhanced microorganism activity. The sulfur + manure treatment increased microbial C and N approximately twofold. Because the manure, sulfur, and gypsum treatments improved the tailings conditions for plant growth, the use of these amendments for mine tailing reclamation was strongly recommended. Across all treatments, cedar and black pine demonstrated 83 and 77% survival rates for the first 3 years of afforestation, respectively. For the same period, the black locust survival rate was 35% lower than that of the other species. The gypsum + manure application increased seedling height growth by about 20% for all three species compared to the other treatments.     

Effect of organic soil amendments on the incidence of stalk rot of maize

Five organic materials, Calopogonium sp. leaves, rice straw, mixed wood saw dust of Terminalia sp. Triplochyton sp. and Kaya sp., fresh guinea grass and poultry manure were added to soil with a recent history of high stalk rot of maize caused by Macrophomina phaseolina and Fusarium moniliforme. The two stalk rot organisms reacted differently to the organic amendments. All the amendments produced significantly less Fusarium stalk rot disease than the unamended control. Amendment of soil with fresh Calopogonium leaves was almost ineffective in controlling the incidence of Macrophomina phaseolina. Organic amendment with poultry manure increased the disease casued by M. phaseolina. The other amendments appeared to be equally effective in checking the disease. Increased microbial population due to amendment may play some role in disease suppression.     

Changes in microbial biomass indices after 10 years of farmyard manure and vegetal fertilizer application to a sandy soil under organic management

The main objective of the second Darmstadt trial was to investigate the effects of vegetal fertilizers on soil properties and crop yield in comparison with farmyard manure. The experiment consisted of seven treatments: (i) inorganic fertilizers, (ii) vegetal organic fertilizers, (iii) vegetal organic fertilizers equivalent to biodynamic preparations, (iv) cattle farmyard manure, (v) cattle farmyard manure with addition of biodynamic preparations, (vi) high level of cattle farmyard manure, and (vii) high level of cattle farmyard manure with biodynamic preparations. The soil properties analyzed were pH, soil organic C, N, P, and S, soil microbial biomass C, N, and P, basal respiration and fungal ergosterol. The application of vegetal fertilizers had slightly negative effects on soil organic C, no effects on crop yield (potato, winter rye) and microbial biomass, but positive effects on ergosterol in comparison with farmyard manure. The increase in ergosterol was caused by straw return in the vegetal, but also in the inorganic fertilizer treatments. The biodynamic preparations did not affect the contents of soil organic C and total N. The low effectiveness of vegetal fertiliser in maintaining soil organic C levels is of particular importance for organic cropping systems and should be examined further under different site conditions.     

Effects of long-term fertilization on AM fungal community structure and Glomalin-related soil protein in the Loess Plateau of China

Arbuscular mycorrhizal fungi (AMF) are crucial for ecosystem functioning, and thus have potential use for sustainable agriculture. In this study, we investigated the impact of organic and mineral fertilizers on the AMF community composition and content of Glomalin-related soil protein (GRSP) in a field experimental station which was established in 1979, in the Loess Plateau of China. Roots and soils were sampled three times during the growing period of winter wheat in 2008. The treatments including: N (inorganic N), NP (inorganic N and P), SNP (straw, inorganic N and P), M (farmyard manure), MNP (farmyard manure, inorganic N and P), and CK (no fertilization). AMF communities of root and soil samples were analyzed using PCR-DGGE, cloning and sequencing techniques; and GRSP content was determined by Bradford assay. Our results indicated that spore density, GRSP, and AMF community varied significantly in soils of long-term fertilization plots at three different wheat growing stages. The effects of wheat growing period on AMF community in roots were much more evident than fertilization regimes. However, the diversity of AMF was low in our study field. Up to five AMF phylotypes appeared in each sample, with the overwhelming dominance of a Glomus-like phylotype affiliated to G. mosseae. GRSP content was correlated positively with organic carbon, total phosphorus, available phosphorus, soil pH, and spore densities, but correlated negatively with soil C/N (P?<?0.05). The results of our study highlight that the richness of AMF in Loess Plateau agricultural region is low, and long-term fertilization, especially amendments with manure and straw, has beneficial effects on accumulation of soil organic carbon, spore density, GRSP content, and AMF diversity. Host phenology, edaphic factors (influenced by long-term fertilization), and habitats interacted to affect the AMF community and agoecosystem functioning. Additionally, soil moisture and pH make a greater contribution than other determined soil parameters to the AMF community dynamics in such a special semi-arid agroecosystem where crops rely greatly on rainfall.