Adsorption and degradation of three pesticides in a vineyard soil and in an organic biomix

none5noA soil and an organic biomix (soil/vine branch/garden compost 20/40/40) were used in this lab experiment to evaluate adsorption and degradation parameters for three pesticides (chlorpyrifos, metalaxyl and cymoxanil) used in a vineyard. Adsorption in the biomix material was higher than in the soil for the three pesticides and chlorpyrifos was the most adsorbed pesticide. The role of the organic carbon is essential for enhancing the adsortion of the three pesticides, especially for the most apolar chlorpyrifos. Degradation was generally faster in the biomix material than in the soil although the process was slower in the case of chlorpyrifos if compared with the other two chemicals, due to a more toxic eect of this pesticide on soil microflora and a larger adsorption of this pesticide on the organic biomix that reduces its availability for dissipation. Amendment with cheap and available organic wastes or a grass-covered management of soil in the vineyard could reduce the impact of pesticides in the vineyard ecosystem and contribute to the sustainable management of chemicals in the environment.openCostantino Vischetti, Elga Monaci, Cristiano Casucci, Arianna De Bernardi, Alessandra CardinaliVischetti, Costantino; Monaci, Elga; Casucci, Cristiano; DE BERNARDI, Arianna; Cardinali, Alessandr

Pollutants transfer from soil to water: geochemical investigation in different watersheds

Surface water, groundwater, phytosanitary products, soil, isotope

Soil nitrogen and weed biodiversity: An assessment under two orchard floor management practices in NVZ (Italy).

none6openMd Jebu Mia, Elga Monaci, Giorgio Murri, Francesca Massetani, Jacopo Facchi, Davide NeriMia, MD JEBU; Monaci, Elga; Murri, Giorgio; Massetani, Francesca; Facchi, Jacopo; Neri, David

Nitrogen and chlorophyll status determination in durum wheat as influenced by fertilization and soil management: Preliminary results.

Handheld chlorophyll meters as Soil Plant Analysis Development (SPAD) have proven to be useful tools for rapid, no-destructive assessment of chlorophyll and nitrogen status in various crops. This method is used to diagnose the need of nitrogen fertilization to improve the efficiency of the agricultural system and to minimize nitrogen losses and deficiency. The objective of this study is to evaluate the effect of repeated conservative agriculture practices on the SPAD readings, leaves chlorophyll concentration and Nitrogen Nutrition Index (NNI) relationships in durum wheat under Mediterranean conditions. The experimental site is a part of a long-term-experiment established in 1994 and is still on-going where three tillage managements and three nitrogen fertilizer treatments were repeated in the same plots every year. We observed a linear relationship between the SPAD readings performed in the central and distal portion of the leaf (R2 = 0.96). In fertilized durum wheat, we found all positive exponential relationships between SPAD readings, chlorophyll leaves concentration (R2 = 0.85) and NNI (R2 = 0.89). In the unfertilized treatment, the SPAD has a good attitude to estimate leaves chlorophyll concentration (R2 = 0.74) and NNI (R2 = 0.77) only in crop grow a soil with relative high content of soil organic matter and nitrogen availability, as observed in the no tilled plots. The results show that the SPAD can be used for a correct assessment of chlorophyll and nitrogen status in durum wheat but also to evaluate indirectly the content of soil organic matter and nitrogen availability during different growth stages of the crop cycle

Effect of contrasting crop rotation systems on soil chemical and biochemical properties and plant root growth in organic farming: First results

Organic farming is claimed to improve soil fertility. Nonetheless, among organic practices, net C-inputs may largely vary in amount and composition and produce different soil conditions for microbial activity and plant-root system adaptation and development. In this study, we hypothesised that, in the regime of organic agriculture, soil chemical and biochemical properties can substantially differ under contrasting crop rotation systems and produce conditions of soil fertility to which the plant responds through diverse growth and production. The impact of 13 years of Alfalfa-Crop rotation (P-C) and Annual Crop rotation (A-C) was evaluated on the build up of soil organic carbon (SOC), active (light fraction organic matter, LFOM; water soluble organic carbon, WSOC) and humic fraction (fulvic acids carbon, FAC; humic acids carbon, HAC), soil biochemical properties (microbial biomass carbon, MBC; basal respiration, dBR; alkaline phosphatase AmP; arylsulfatase ArS; orto-diphenoloxidase, o-DPO) and the amount of available macro-nutrients (N, P, and S) at two different soil depths (0-10 cm and 10-30 cm) before and after cultivation of wheat. We also studied the response of root morphology, physiology and yield of the plant-root system of wheat. Results showed that the level of soil fertility and plant-root system behaviour substantially differed under the two crop rotation systems investigated here. We observed high efficiency of the P-C soil in the build up of soil organic carbon, as it was 2.9 times higher than that measured in the A-C soil. With the exception of o-DPO, P-C soil always showed a higher level of AmP and ArS activity and an initial lower amount of available P and S. The P-C soil showed higher rootability and promoted thinner roots and higher root density. In the P-C soil conditions, the photosynthesis and yield of durum wheat were also favoured. Finally, cultivation of wheat caused an overall depletion of the accrued fertility of soil, mainly evident in the P-C soil, which maintained a residual higher level of all the chemical and biochemical properties tested

Effect of recycling wood ash on microbiological and biochemical properties of soils

Wood ash production is increasing due to the increasing use of wood as a sustainable fuel. Wood ash can be recycled in crop soils as a source of nutrients and as a liming agent to correct soil acidity. However, the effect of wood ash on soil quality is poorly known. Here we studied the effect of addition of wood ash at 5 and 20 t ha–1 on microbial and biochemical properties in samples from the 0–30 cm surface of three neutral and two alkaline agricultural soils. The samples were incubated for one year at 25 °C and 60% water-holding capacity. The soil microbiological biomass (microbial biomass C and N), general microbial activity using fluorescein diacetate hydrolysis, and alkaline phosphatase, arylsulphatase, catalase and o-diphenoloxidase activities were determined periodically together with pH and electrical conductivity. Increases in microbial biomass C and fluorescein diacetate hydrolysis occurred at the lower wood-ash dose, whereas microbial biomass C decreased at the higher wood-ash dose over the entire period, and the fluorescein diacetate hydrolysis after 4 months. The microbial C/N ratios of treated samples were significantly different with respect to that of the control, suggesting changes in the structure of the microbial communities. The changes in microbial biomass and microbial activity were related to the increases in pH, which induce the development of bacteria to the detriment of fungi, to the electrical conductivity, and to the nutrient levels after wood-ash addition. Alkaline phosphatase and arylsulphatase activities were weakly inhibited at 20 t ha–1, and catalase activity was stimulated in the neutral samples and inhibited in the alkaline samples. The highest o-diphenoloxidase activity observed throughout in all of the treated samples may suggest a decrease in the mineralisation process. Our findings reveal that the soil biochemical parameters investigated are significantly affected only in some cases at 20 t ha–1, suggesting that a treatment exceeding 5 t ha–1 is not recommended until the agro-chemical and physical functions of the soil are further studied

Nitrogen release from pelletized poultry fertilizer in two soils: influence of soil moisture and microbial biomass

Nitrogen release from organic amendments, e.g., from organic agriculture, is a key process to raise soil fertility to sustain crop production in low environmental impact agroecosystems. This study aimed to investigate nitrogen release from a pelletized organic amendment containing poultry litter, guano and pot ale applied to soil from a field under two different management systems: an alfalfa-based crop rotation, enriched with N by the legume, under low-intensity tillage and a cereal-sunflower crop rotation under high-intensity tillage. Both sample types were evaluated under different temperature and soil moisture conditions (optimal and variable). The influence of the released amount of N-NO3 on soil microbial biomass, soil basal respiration as well as on β-glucosidase, alkaline phosphatase and o-diphenoloxidase were investigated. The soil fertility level under low-intensity was higher than under high-intensity tillage. Consequently, compared to the control, microbial biomass growth in pellet-treated samples was intensified, both under optimal and variable conditions. Nevertheless, at the end of the experiment under variable conditions, microbial biomass decreased down to the level of the control. Soil moisture was identified as the limiting factor for basal respiration in low-tillage soil, while in the intensively tilled soil, low fertility was limiting, and respiration increased in response to pellet application, supplying C for microbial biomass. During the experimental period, the investigated enzyme activities were somewhat intensified by pellet application, contributing slightly to improve soil biochemical fertility. More N-NO3 was released from soil under low than high-intensity tillage; however after 90-days, the pellet was not completely mineralized, and even at optimal soil moisture content, nitrate release was only partial. This indicated that pelletizing, though useful for practical reasons such as handling, storage and field distribution, can reduce the fertilization efficiency of organic amendments

Nitrogen release from pelletized poultry fertilizer in two soils: influence of soil moisture and microbial biomass

Texto completoNitrogen release from organic amendments, e.g., from organic agriculture, is a key process to raise soil fertility to sustain crop production in low environmental impact agroecosystems. This study aimed to investigate nitrogen release from a pelletized organic amendment containing poultry litter, guano and pot ale applied to soil from a field under two different management systems: an alfalfa-based crop rotation, enriched with N by the legume, under low-intensity tillage and a cereal-sunflower crop rotation under high-intensity tillage. Both sample types were evaluated under different temperature and soil moisture conditions (optimal and variable). The influence of the released amount of N-NO 3 on soil microbial biomass, soil basal respiration as well as on β-glucosidase, alkaline phosphatase and o-diphenoloxidase were investigated. The soil fertility level under low-intensity was higher than under high-intensity tillage. Consequently, compared to the control, microbial biomass growth in pellet-treated samples was intensified, both under optimal and variable conditions. Nevertheless, at the end of the experiment under variable conditions, microbial biomass decreased down to the level of the control. Soil moisture was identified as the limiting factor for basal respiration in low-tillage soil, while in the intensively tilled soil, low fertility was limiting, and respiration increased in response to pellet application, supplying C for microbial biomass. During the experimental period, the investigated enzyme activities were somewhat intensified by pellet application, contributing slightly to improve soil biochemical fertility. More N-NO 3 was released from soil under low than high-intensity tillage; however after 90-days, the pellet was not completely mineralized, and even at optimal soil moisture content, nitrate release was only partial. This indicated that pelletizing, though useful for practical reasons such as handling, storage and field distribution, can reduce the fertilization efficiency of organic amendments