Combination Of Organic Amendments Research Articles

Effects of bio-fertiliser enriched organic amendments on flowering and fruiting behaviour, yield and quality attributes of Khasi mandarin (Citrus reticulata Blanco)

ABSTRACT Organic farming has emerged as an important priority area in view of the growing demand for safe and healthy food and long-term sustainability of agricultural systems. This case study investigated the effects of organic amendments on growth, flowering and fruiting behaviour, yield and quality attributes of Khasi mandarin (Citrus reticulata Blanco) grown at Mizoram University, Aizawl, India. The study included 13 treatments comprising of various combinations of organic amendments, farm-yard manure (FYM), vermicompost (VC), pig manure (PM), mustard oil cake (MOC), and bio-fertilisers Azospirillum, Azotobacter, phosphate solubilising bacteria (PSB), potash solubilising bacteria (KSB) and arbuscular mycorrhizal fungi (AMF). The results revealed that bio-fertiliser enriched organic amendments enhanced flowering and fruiting, yields and quality attributes of Khasi mandarin. Among the different combinations, the greatest plant height, girth, canopy spread, canopy volume, fruit weight, length, diameter, fruit volume, pulp weight, pulp-to-peel ratio, pulp thickness, number of segments and lowest unmarketable yield were obtained with VC + Azotobacter + AMF + KSB. The treatment with FYM + Azotobacter + AMF + KSB recorded the highest fruit set, fruit retention, marketable fruits, fruit yield and lowest fruit drop, and for the fruit quality parameters, the maximum TSS, reducing sugar, non-reducing sugar, total sugar, sugar:acid ratio, ascorbic acid and lowest acidity. It was concluded that these two treatments can be recommended to achieve significant improvement in flowering and fruiting behaviour and yield and quality of Khasi mandarin.

Effects of organic amendments, biofertilisers and biodynamic preparations on soil properties and leaf nutrient concentrations in grapevine

ABSTRACT Excessive and unbalanced use of chemical fertilisers can lead to depletion of physical and chemical properties of the soil and have negative impacts on the environment. This investigation was conducted at Mizoram University, Aizawl, Mizoram, India and aimed to evaluate effects of organic amendments, biofertilisers and biodynamic preparations on soil properties and leaf nutrient status of grapevine. The experiment was laid out in randomised block design with 14 treatments consisting of different combinations of organic amendments, biofertilisers and biodynamic preparations viz. farmyard manure (FYM), vermicompost (VC), pig manure (PIM), neem cake (NC), Azospirillum, phosphate solubilising bacteria (PSB), potash solubilising bacteria (KSB), Trichoderma harzianum, cow pat pit (CPP) and biodynamic preparations BD500 and BD501. The results demonstrated that the use of organic amendments in combination with biofertilisers and biodynamic preparations enhanced leaf nutrient status as well soil properties in the vineyard. Among all the tested combinations, the highest concentrations of Mn, Zn, chlorophyll a, b and total chlorophyll in the leaves and concentrations of soil organic carbon, inorganic carbon, total carbon, total N, available N, P, K, Mn and Zn, cation exchange capacity (CEC) and abundance of bacteria and Actinomycetes in the soil were recorded with application of PIM + Azospirillum + PSB + KSB + T. harzianum + CPP + BD 500 + BD 501. This treatment was therefore recommended as a suitable option to meet the demand for long-term maintenance of soil fertility as well agroecosystem conservation and sustainability.

Combination of organic amendments as a soil recovering strategy at a desertification hotspot in the Brazilian semiarid

AbstractThe use of manure, organic mulch, and legume‐based fertilizers can increase soil fertility in semiarid regions. However, the effects of such practices on soils prone to desertification are unknown. This study aimed to evaluate soil fertility and herbaceous stratum yield on soils amended with different organic inputs in the desertification hotspot of Irauçuba, Ceará state, Brazil. The experiments were performed in two areas with different soils (Planosol and Cambisol), in randomized blocks with a 2 × 2 × 3 + 1 factorial design. The factors consisted of (i) mulch (presence or absence of Copernicia prunifera [carnauba palm] straw), (ii) manure (sheep or cattle), and (iii) legume‐based fertilizer (Mimosa tenuiflora [jurema], Mimosa caesalpiniifolia [sabiá], and Leucaena leucocephala [leucena]), in addition to an untreated control, with three replicates. Soil chemical attributes and herbaceous stratum yield were assessed in the two areas. Positive effects of the combined use of carnauba palm straw, manures, and legume‐based fertilizers on soil fertility were more evident for Planosol than for Cambisol. The combination of sheep manure with sabiá‐based fertilizer in Planosol, and cattle manure and leucena‐based fertilizer in Cambisol increased herbaceous stratum yield. Herbaceous stratum yield in Planosol is more responsive to the input of great amounts of soil nutrients (especially P) and it increases soil organic matter levels, while in Cambisol, herbaceous stratum yield is more associated with the ability of inputs to make nutrients readily available. The use of organic amendments can reverse, in the short‐term, degradation and desertification processes of soils in the Brazilian semiarid region.

Efficacy of cattle manure in improving the productivity of peanut (Arachis hypogaea) in sandy soil of Central Vietnam

Peanut is an important annual crop in sandy soil of Central Vietnam. Organic fertilizer application plays a key role in improving peanut yield and soil quality. However, research on cattle manure is still limited in sandy soil for peanut crop. Trial consisted of 10 fertilizer treatments with two factors including two application methods and five ratios of inorganic fertilizer and manure and rice straw combinations. They were arranged in a split plot design with three replicates during the spring and summer season of 2021 on the sandy soil at Cat Trinh commune, Phu Cat district, Binh Dinh province, Vietnam. The aims of the study were to evaluate the efficiency of different combinations of organic amendments on the yield of peanut and to examine possible short-term changes in soil characteristics as a result of organic amendments application. The study results showed that application methods and different organic treatments gave higher yields compared with application of inorganic fertilizer alone. The highest peanut yield was found in the application of organic fertilizer from cattle manure+rice straw (1:0.5) and row application with (2.80-3.85 t/ha), increasing (21-27%) compared with application of inorganic fertilizer alone in surface application method and seasons. Cattle manure application improved some soil chemistry properties after the experiment such as OC, CEC, total N, P2O5 and K2O. In conclusion, incorporation of different types of organic amendments improved peanut yield and soil properties more than application of inorganic fertilizer alone.

Integrated use of organic amendments increased mungbean (Vigna radiata (L.) Wilczek) yield and its components compared to inorganic fertilizers

AbstractRainfall variability, low soil organic matter content, and costly inorganic fertilizers are the major agricultural constraints in Sub‐Saharan Africa. Integrated use of compost and manure is essential for sustaining soil fertility and increasing crop productivity. This study was conducted to evaluate the combined effects of compost and animal manure on mungbean growth and yield. The 12 treatments consisted of control, recommended dose of nitrogen, phosphorus, and potassium (NPK), 5 ton ha−1 of compost, 10 ton ha−1 of poultry, 10 ton ha−1 of cattle, and 10 ton ha−1 of sheep manure, and six combinations of organic amendments with 50% of their applied rate alone. These treatments were laid out in a randomized complete block design with six replications. Application of cattle manure at 10 ton ha−1 significantly increased mungbean seed yield by 66% and 84% compared to the recommended rate of NPK and control treatments, respectively. Similar observations were made on stem diameter, total pod weight, and number of seeds per pod. Plants amended with compost had the highest number of ramifications and number of pods than NPK fertilized plants, which recorded (9±) ramifications and (27±) pods per plant. On average, integrated use of 5 ton ha−1 of poultry manure + 5 ton ha−1 of cattle manure had the highest soil plant analysis development values, though not significantly different from NPK fertilizers. These results suggest that application of organic amendments could be an alternative to costly and inaccessible inorganic fertilizers for improving mungbean productivity under low‐input agriculture systems.

Growth Performances of BRRI dhan55 under Integrated Nutrient Management

Integrated nutrient management is vital for the development and growth of rice (Oryza sativa L.), but they are rarely used nowadays due to the widespread use of inorganic fertilizers. So, the current research was executed to determine the effect of organic amendments on different growth parameters of BRRI dhan55. A field investigation was managed at the Plant Pathology field lab, Sylhet Agricultural University, from November 2018 to April 2019. Different combinations of organic amendments (T1= Recommended Fertilizer Dose, RFD which includes TSP 100g 10 m-2, MoP 100g 10 m-2, Gypsum 50g 10 m-2, Zinc 15g 10 m-2, T2= RFD with vermicompost 2kg 10 m-2, T3= RFD with vermicompost 4 kg 10 m-2, T4= RFD with cowdung 2 kg 10 m-2, T5= RFD with cowdung 4 kg 10 m-2, and T6= RFD with Biochar 4 kg 10 m-2) were used in a RCBD (Randomized Complete Block Design) with three replications. The existing results showed that RFD with biochar treatments showed better performance in terms of the initial weight of grain (50.70 g), clean grain weight (48.55 g), and number of non-effective grains per panicle (27.67) and tiller per hill (12.07). T2 (RFD with vermicompost 2 kg 10 m-2) treatments demonstrated better results in parameters such as weight of grain from a single panicle (4.04 g), single panicle grain weight (3.90 g), panicle length (24.77 cm), and grain per panicle (153.00). Biomass (34.56 g) and above-ground length parameters (90.00 cm) performed better with the T4 treatment (RFD with 2 kg 10 m-2 of cowdung). T6 treatments were showed the highest grain yield (10.71 t ha-1) followed by T3 treatments. Therefore, the present results recommended that organic amendments could be a better supplement than inorganic amendments for the growth performance of BRRI dhan55.

The Effect of Palm Bunch Ash and Wood Ash on the Growth and Yield of Fluted Pumpkin (Telfaria Occidentalis)

This study was designed to investigate the effect of Palm Bunch and wood ash on the growth and yield performance of fluted pumpkin (Telfairia occidentalis). The Study was carried out at Federal Polytechnic Nekede, Student Research Farm. The Nekede soil is sandy loam textured, with pH value as low as 4.8 and very deficient in OM and N. Amelioration treatments were carried out by adding organic supplements (palm bunch ash and wood ash) to the soil. The study used a randomized complete block design with 10 t/ha palm bunch ash (PBA), 10 t/ha wood shave ash (WA), 5 t/ha PBA + 5 t/ha WA and a control (no additives added), making a total of four treatments. The treatments were replicated three times. The experimental works were undertaken in field plots. The growth parameters examined were: Plant height, leaf number and vine length and shoot/root ratio, fresh weight. Data collected were subjected to statistical analysis using least significant difference (LSD). Results of the studies showed that sole application of 10 t/ha PBA and 10 t/ha WA and halved their rates in combination, increased soil pH, N, OC, P, K, Ca and Mg in relation to the control treatment. Combination of palm bunch ash (PBA) and wood ash (WA) significantly enhanced yield in fluted pumpkin (Telfairia occidentalis). The study reveals that soil acidity could be neutralized; soil fertility improved and crop yield enhanced with a combination of organic amendments on the ultisols of south-eastern Nigeria.

Interaction of soil health indicators to different regenerative farming practices on mineral soils

AbstractRegenerative farming is a common practice adopted to enhance soil health. Routinely, cheaply measured soil health indicators can be used to predict unknown soil health indicators, which makes analysis simple and fast. The objective of this study was to determine the interaction and relationship between soil health indicators and the effects of regenerative farming practices on soil health indicators. We conducted a comprehensive on‐farm study across Florida, measuring 11 soil health indicators for 592 soil samples that were collected from the surface 15 cm of soil on 13 experimental sites. Sampled fields were conventionally managed or subjected to either cover cropping, organic amendment application, or their combination, and fallow fields as control plots. We tested the Pearson correlation coefficient between 11 soil health indicators and further tested the types of relationships between each indicator using regression analysis. Strong positive correlations (r ≥ + .5 to 1.0) were obtained, especially between organic matter (OM) with maximum water holding capacity (MWHC), cation exchange capacity (CEC), soil protein (SP), and total Kjeldahl nitrogen (TKN); MWHC with CEC, SP, and TKN; TKN with CEC and SP; total phosphorus (TP) with Mehlich‐3 phosphorus (M3P). A strong negative correlation (r ≥ –.5 to –1.0) was observed between bulk density (BD) with OM, MWHC, CEC, and TKN. No significant change in soil health indicators was observed in control plots except for active carbon (AC) and CEC. Organic amendments and a combination of organic amendments with cover crops were effective in improving soil health indicators. However, cover crops alone had no effect on soil health indicators except for CEC and M3K.

Efficacy of vermicompost and biochar on the growth and yield of green cabbage

Organic production of Green Cabbage may ensure the nutritional status and food safety for the consumers, but maintaining the productivity and economic viability of inorganic production is almost impossible for farmers of Bangladesh. At this context, a study was carried out at the Horticulture farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the period from October 2017 to March 2018 to evaluate the efficacy of vermicompost and biochar on agronomic properties and economic of cabbage. Four biochar treatments, ( B0: 0 t ha-1 biochar, B1 :2 t ha-1 , B2 :6 t ha-1 and B3 :10 t ha-1) and three vermicompost treatments (Vc0 : 0 t ha-1, Vc1 :4 t ha-1 and Vc2 :8 t ha-1 ) were selected. B0Vc0 was considered as control. The results revealed that maximum highest plant height, number of leaves plant-1, leaf length, leaf breadth and plant spread were obtained when the B3 was mixed withVc2. But the thickness of head (10.29 cm), diameter of head (16.66 cm), % dry matter of cabbage (14.93%), weight of cabbage head plant-1 (1370 g) and yield of cabbage (52.75 t ha-1) were obtained from the treatment combination of B2Vc2. In terms of economic sustainability, the net return (Tk 523598) with highest BCR (3.70) was obtained from the treatment combination of B1Vc1.These results provide prove the effectiveness of biochar and vermicompost in sustainable Cabbage production. It also provides baseline guidelines for further investigation of choosing the appropriate combination of organic amendments based on crop requirement to maximize economic value. Asian Australas. J. Biosci. Biotechnol. 2021, 6 (2), 68-74

Can biochar and chitin as organic soil amendments be alternatives to manures for rocket (Eruca sativa Mill.) growth?

Organic amendments are sustainable, and relatively cheap materials derived from plants and animals that are supplemented into the soil for the restoration of the soil’s physical and chemical properties, and provide the plants' nutrients before seeding, increasing its productivity. The addition of organic amendments to agricultural soil is recommended to improve soil functions and plant growth. The objective of this study was to evaluate the impact of different organic soil amendments (biochar chitin, horse, sheep manure) on the growth of rocket plants (Eruca sativa Mill.) and answer if biochar and chitin can be alternatives to manures. This study was conducted in pots, under various combinations of organic amendments, using a typic xerofluvent agricultural soil, in the spring of 2016. To experiment, four organic amendments (biochar, chitin from shrimp shells, horse and sheep manure) were employed to amend the soil, in a completely randomized design, analyzing the impact of 4% and 8% biochar, 2% and 3% chitin, as well as 2% and 5% horse or sheep manure on the growth of rocket (Eruca sativa Mill.). According to the findings, the best growth rate of the rocket was found in the sheep manure amendment at 2% rate, followed by the 5% rate, in the horse manure amendments at 2% and 5% rates, in the biochar amendment at 4% rate, and in chitin at 3% and 2% rates consecutively. Positive effects of organic amendments on plant growth were more evident under the amendments related to sheep manure at a 2% rate.

Predicting the abatement rates of soil organic carbon sequestration management in Western European vineyards using random forest regression

The implementation of soil organic carbon sequestration (SCS) practices on agricultural land has the potential to help to mitigate climate change at the global level. However, our understanding of the extent to which viticultural soils can contribute to this global effort remains limited. In this study, we used a random forest regression to predict the change in soil organic carbon stocks in vineyards of Western Europe under five SCS practices: organic amendments (OA), cover cropping (CC), organic amendments and no-tillage (OA+NT), no-tillage and cover cropping (NT+CC), and a combination of organic amendments, no-tillage and cover cropping (OA+NT+CC). The abatement rate of each SCS practice was modelled and mapped for six countries in Western Europe: Spain, France, Italy, Portugal, Germany and Austria. Overall, the highest abatement rate was reached under OA+NT+CC (8.29 ​Mg CO 2 -eq. ha −1 yr −1 ), whereas the lowest was observed under CC (7.03 Mg CO 2 -eq. ha −1 yr −1 ). Results showed major differences in abatement rates at the regional and national level. Despite these differences, the adoption of SCS practices was associated with a high abatement potential in the six countries and should be encouraged in the viticulture sector as a way to offset greenhouse gas emissions via soil carbon sequestration. • Soil carbon sequestration was modelled in vineyards using random forest regression. • Random forest regression provided accurate predictions. • All modelled practices were associated with high abatement rates in vineyards. • The highest abatement rate was reached in the Canary Islands under OA+NT+CC. • Vineyards can contribute to global climate change mitigation efforts.

Integration of some organic amendments and the predatory nematode, Fictor composticola, for the management of Meloidogyne incognita in cucumber

BackgroundOrganic amendments are well known for influencing soil nematode community structure, diversities, and activities. Most of the previous studies focused on effects of organic amendments on plant-parasitic nematodes, but only a few investigated the effect of combination of biocontrol agents and organic amendments on soil nematodes.Main bodyDifferent organic amendments (neem cake, poultry manure, and neem leaves) were combined with the predatory nematode, Fictor composticola, for the control of root-knot nematode, Meloidogyne incognita, in cucumber. Organic amendments were mixed in pots containing 1 kg soil, 15 days before sowing. Cucumber (cv. CCH-1) plants grown in these pots were inoculated by 2000 J2 of M. incognita and 400 F. composticola per pot, after 1 week of germination. Fictor composticola in combination with chicken manure + neem cake + neem leaves was found the best mixture for reducing the number of galls, egg masses, and final root-knot nematode population. The predator’s population reached the maximum in this treatment. All combinations of organic amendments in the presence of F. composticola were found significantly superior over inoculated check in reducing nematode’s population and in improving plant growth over the un-inoculated check.ConclusionsData indicated the suitability of using the predatory nematode, F. composticola, and organic amendments for potential use in sustainable nematode management strategies.

The combination of quarry restoration strategies in semiarid climate induces different responses in biochemical and microbiological soil properties

Mining activities generate loss of environmental and landscape quality, especially in arid and semiarid Mediterranean regions. A precondition for ecosystem reclamation in such highly disturbed areas is the development of functional soils with sufficient amount of organic matter. In a restoration experiment in limestone quarries in the Sierra de Gádor (Almería), SE Spain, several combinations of organic amendments (sewage sludge and compost from domestic organic waste) and mulches (gravel and woodchip) were tested and native plants (Anthyllis cytisoides, A. terniflora and Macrochloa tenacissima) were planted. After five years, the effect of each treatment on the soil chemical properties, basal respiration, four enzyme activities (dehydrogenase, urease, β-glucosidase and alkaline phosphatase) and the microbial community composition was analysed. Analysis of phospholipid fatty acids (PLFAs) and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprinting were used to analyse the microbial communities (bacteria and fungi). Undisturbed natural soils adjacent to the mining area were used as soil quality references. Organic amendments, particularly compost, improved soil chemical and biochemical properties as well as microbial biomass. However, the effects of mulch application did not show a clear trend with respect to soil functionality and did not increase the microbial biomass. Soils treated with sewage sludge and compost showed bacterial PLFA concentrations similar to those of reference soils, but compost treatments presented fungal PLFA concentrations that were much higher. Each combination of organic amendment and mulch was selective for a proper microbial community. Nevertheless, increases in soil functionality and microbial biomass were not related to changes in microbial diversity. After five years, the microbial properties of restored soils had not yet converged to values recorded in the reference soils. However, the combination of mulches and organic amendments, particularly compost treatment, is suggested to be beneficial for restoring degraded soils from quarrying areas because they stimulate microbial growth and activity, with positive implications for the increase in both soil fertility and quality.

Restoration techniques affect soil organic carbon, glomalin and aggregate stability in degraded soils of a semiarid Mediterranean region

The first step to restoring degraded mine soils from calcareous quarries in semiarid environments, usually without soil structure, mainly consists in creating a structured topsoil with suitable physical, chemical and biological properties. The aim of this study is to determine the effects of organic amendments and mulches on soil aggregate stability and aggregation-associated soil characteristics, six years after beginning experimental restoration in the Gádor Mountains (Almería, SE Spain). Experimental plots were set up to test two organic amendments (sludge and compost) and two mulches (gravel and woodchip) and their respective control plots. Soil samples from neighboring undisturbed soils were used as the quality reference threshold. The tested variables were total organic C (TOC), glomalin-related soil protein (GRSP), easily extractable glomalin-related soil protein (EE-GRSP) and water aggregate stability evaluated by both wet sieving (WS) and water-drop test (WDT). Relationships among the measured soil properties were checked in order to assess the best indicators for the most suited restoration practices. After 6years, the results showed that the combination of organic amendments and mulches enhanced soil aggregate stability and the content of aggregate binding agents such as TOC and glomalin. Nevertheless, the role of organic amendments, especially compost, was more important than mulch treatments in increasing TOC and glomalin, showing the closest values to the undisturbed reference soils (over 30gkg−1 for TOC and 3.5gkg−1 for GRSP). Despite the considerable improvement in water stable aggregates found in sludge-amended plots (average mean weight diameter of 2.13mm in WS, and 25-drop impacts in WDT), the reference soils provided the highest values (average mean weight diameter of 3.32mm in WS, and 99-drop impacts in WDT). The lack of a good correlation between soil structure-related variables restricted the evaluation of the real effects of restoration treatments, and suggested considering other soil properties (e.g., hydrophobicity, hardening) associated to aggregate stability.

Availability and transfer to grain of As, Cd, Cu, Ni, Pb and Zn in a barley agri-system: Impact of biochar, organic and mineral fertilizers

With biochar becoming an emerging soil amendment and a tool to mitigate climate change, there are only a few studies documenting its effects on trace element cycling in agriculture. Zn and Cu are deficient in many human diets, whilst exposures to As, Pb and Cd need to be decreased. Biochar has been shown to affect many of them mainly at a bench or greenhouse scale, but field research is not available. In our experiment we studied the impact of biochar, as well as its interactions with organic (compost and sewage sludge) and mineral fertilisers (NPK and nitrosulfate), on trace element mobility in a Mediterranean agricultural field (east of Madrid, Spain) cropped with barley. At harvesting time, we analysed the soluble fraction, the available fraction (assessed with the diffusive gradients in thin gels technique, DGT) and the concentration of trace elements in barley grain. No treatment was able to significantly increase Zn, Cu or Ni concentration in barley grain, limiting the application for cereal fortification. Biochar helped to reduce Cd and Pb in grain, whereas As concentration slightly increased. Overall biochar amendments demonstrated a potential to decrease Cd uptake in cereals, a substantial pathway of exposure in the Spanish population, whereas mineral fertilisation and sewage sludge increased grain Cd and Pb. In the soil, biochar helped to stabilise Pb and Cd, while marginally increasing As release/mobilisation. Some of the fertilisation practises or treatments increased toxic metals and As solubility in soil, but never to an extent high enough to be considered an environmental risk. Future research may try to fortify Zn, Cu and Ni using other combinations of organic amendments and different parent biomass to produce enriched biochars.

Evaluation of soil reclamation techniques at the Key Lake uranium mine

Olatuyi, S. O. and Leskiw, L. A. 2015. Evaluation of soil reclamation techniques at the Key Lake uranium mine. Can. J. Soil Sci. 95: 153–176. Adequate soil nutrients and water supply are critical to vegetation establishment and creation of sustainable ecosystems in post-disturbed mining sites. This study investigated effects of various amendments and capping techniques on soil quality and moisture distribution on a reclaimed waste rock pile at the Key Lake uranium mine in northern Saskatchewan, Canada. Soil profiles were reconstructed in 2010 using locally available sandy glacial materials to create soil covers of 1 m thickness. The reclamation treatments consisted of a Control plot, commercial peat (Peat), a local lake sediment (Sediment), underlying flax straw (Straw), mulched forest floor and Ae (LFH), fertilizer (NPK), manure pellets (Pellets), and a demonstration plot (Demo) comprised of Sediment, LFH and Pellets. Soil amendments were applied by various techniques as broadcast, surface incorporation, below the surface or surface mounding. Annual plot monitoring was conducted from 2011 to 2013 and soil samples were analyzed for pH, electrical conductivity (EC), sodium adsorption ratio (SAR), available nutrients, cation exchange capacity (CEC), total organic carbon (TOC), total nitrogen (TN), and regulated metals. Volumetric moisture contents were measured periodically to examine soil moisture response to growing-season precipitation. In 2013, the topsoil of the Control plot was slightly acidic (pH of 6.3) while the Sediment and Demo plots had the lowest pH of 4.0. The EC and SAR values were below 1.0 in all treatment plots. The highest levels of available N, TN, TOC and CEC were in the Sediment and Demo plots, followed by the Peat. The concentration of arsenic exceeded the regulatory limit by 3.4- and 2.6-fold in the Sediment and Demo topsoil, respectively, while concentrations of other metals were below the limits in all treatment plots. The Sediment and Demo treatments were most effective in retaining water in the topsoil, while application of soil amendment by mounding enhanced infiltration and water transmission in the profile. In terms of soil fertility and moisture storage, the combination of organic amendments in multi-layers plus surface mounding, as in the Demo plot, is the most promising capping technique for restoring soil health, vegetative cover and ecosystem functions on the waste rock pile.

Effect of Simulated Soil Solarization and Organic Amendments on Fusarium Wilt of Rocket and Basil Under Controlled Conditions

Pot trials were carried out under controlled conditions to evaluate the effectiveness against Fusarium wilt of rocket (Fusarium oxysporum f.sp. conglutinans) and basil (F. oxysporum f.sp. basilici) of soil amendments based on a patented formulation of Brassica carinata defatted seed meal and compost, combined or not with a simulation of soil solarization. The soil solarization treatment was carried out in a growth chamber by heating the soil for 7 and 14 days at optimal (55–52°C for 6 h, 50–48°C for 8 h and 47–45°C for 10 h/day) and sub-optimal (50–48°C for 6 h, 45–43°C for 8 h and 40–38°C for 10 h/day) temperatures similar to those observed in summer in solarized soil in greenhouses in Northern Italy. Two subsequent cycles of plant cultivation were carried out in the same soil. Even at sub-optimal temperature regimes, 7 days of thermal treatment provided very valuable results in terms of disease control on both rocket and basil. In general, the thermal treatment was more effective against F. oxysporum f.sp. basilici than against F. oxysporum f.sp. conglutinans. Control of Fusarium wilt of rocket is improved with 14 days of thermal treatment. The combination of organic amendments with a short period of soil solarization (7 or 14 days), although not providing any improvement to the level of disease management, did significantly increase biomass and positively affected yield.

Limitations on orchid recruitment: not a simple picture

Mycorrhizal fungi have substantial potential to influence plant distribution, especially in specialized orchids and mycoheterotrophic plants. However, little is known about environmental factors that influence the distribution of mycorrhizal fungi. Previous studies using seed packets have been unable to distinguish whether germination patterns resulted from the distribution of appropriate edaphic conditions or the distribution of host fungi, as these cannot be separated using seed packets alone. We used a combination of organic amendments, seed packets and molecular assessment of soil fungi required by three terrestrial orchid species to separate direct and indirect effects of fungi and environmental conditions on both seed germination and subsequent protocorm development. We found that locations with abundant mycorrhizal fungi were most likely to support seed germination and greater growth for all three orchids. Organic amendments affected germination primarily by affecting the abundance of appropriate mycorrhizal fungi. However, fungi associated with the three orchid species were affected differently by the organic amendments and by forest successional stage. The results of this study help contextualize the importance of fungal distribution and abundance to the population dynamics of plants with specific mycorrhizal requirements. Such phenomena may also be important for plants with more general mycorrhizal associations.

Soil organic amendments and mineral fertilizers: options for sustainable lowland rice production in the forest agro-ecology of Ghana <BR><BR>Rectification organique des sols et engrais chimiques: options pour la production durable du riz dans les terrains bas dans l'agro-ecologie des forets du Ghana

The “sawah” technology (bunded and leveled irrigated rice field) was introduced to some farmers within the forest agro-ecology of Ghana. To improve the productivity of their soils and also to minimize expenditure on mineral fertilizers, the effect of three organic amendments on rice yield was evaluated. Poultry manure, cattle manure and rice husk were used either solely or in combination with mineral fertilizer on rice at three different locations within the forest agro-ecological zone at Potrikrom, Biemso No. 1 and Biemso No. 2. Sole organic amendments were applied at a rate of 7.0 t ha-1 and sole mineral fertilizer was applied as N-P-K at 90-60-60 kg ha-1. The N source was either urea or sulphate of ammonia, P source was triple super phosphate and K source was muriate of potash. Combinations were half rate (organic amendments + mineral fertilizer). Results showed that organic amendments, mineral fertilizer and their combinations significantly contributed to the growth and grain yield of rice. A combination of poultry manure (half rate) and mineral fertilizer (half rate) gave significantly greater grain yield than all the treatments except mineral fertilizer (full rate) at two out of the three locations. Rice grain yields were 6.2, 7.3 and 3.7 t ha-1 for half rate poultry manure + half rate mineral fertilizer at Potrikrom, Biemso No. 1 and Biemso No. 2 respectively, while full rate mineral fertilizer gave 6.6, 7.3 and 3.9 t ha-1 at the three sites respectively. In addition, a combination of organic amendments with mineral fertilizer out-yielded sole organic amendments at all the three sites. Organic amendments applied solely performed in the order: poultry manure > cattle manure > rice husk. Keywords: agro-ecology, forest, organic amendments, “sawah”, sustainability Agricultural and Food Science Journal of Ghana Vol. 3 2004: 237-248

Using a crop/soil simulation model and GIS techniques to assess methane emissions from rice fields in Asia. IV. Upscaling to national levels.

The process-based crop/soil model MERES (Methane Emissions from Rice EcoSystems) was used together with daily weather data, spatial soil data, and rice-growing statistics to estimate the annual methane (CH4) emissions from China, India, Indonesia, Philippines, and Thailand under various crop management scenarios. Four crop management scenarios were considered: (a) a 'baseline' scenario assuming no addition of organic amendments or field drainage during the growing season, (b) addition of 3,000 kg DM ha−1 of green manure at the start of the season but no field drainage, (c) no organic amendments but drainage of the field for a 14-d period in the middle of the season and again at the end of the season, and (d) addition of 3,000 kg DM ha−1 of green manure and field drainage in the middle and end of the season. For each scenario, simulations were made at each location for irrigated and rainfed rice ecosystems in the main rice-growing season, and for irrigated rice in the second (or 'dry') season. Overall annual emissions (Tg CH4 yr−1) for a province/district were calculated by multiplying the rates of CH4 emission (kg CH4 ha−1 yr−1) by the area of rice grown in each ecosystem and in each season obtained from the Huke and Huke (1997) database of rice production. Using the baseline scenario, annual CH4 emissions for China, India, Indonesia, Philippines, and Thailand were calculated to be 3.73, 2.14, 1.65, 0.14, and 0.18 Tg CH4 yr−1, respectively. Addition of 3,000 kg DM ha−1 green manure at the start of the season increased emissions by an average of 128% across the five countries, with a range of 74–259%. Drainage of the field in the middle and at the end of the season reduced emissions by an average of 13% across the five countries, with a range of −10% to −39%. The combination of organic amendments and field drainage resulted in an increase in emissions by an average of 86% across the five countries, with a range of 15–176%. The sum of CH4 emissions from these five countries, comprising about 70% of the global rice area, ranged from 6.49 to 17.42 Tg CH4 yr−1, depending on the crop management scenario.