F. Gustin

Influence of cow manure and composts on the effects of chlorfenvinphos on field crops.

Cauliflower crops were grown in several regions and seasons (spring and summer). Five days after planting, the plants were treated against the root fly by pouring onto soil around the plant stem an emulsion of chlorfenvinphos [2-chloro-1-(2,4-dichlorophenyl) ethenyl diethyl phosphate] in water. The fields were divided into plots. Onto each plot, one of the organic fertilizers, city refuse compost, mushroom cultivation compost, or cow manure was applied at the rate of 100 tons/ha, 1 or 3.5 months before the insecticide treatment. There were also control plots which were not treated with any of the organic fertilizers. During the first 50 days crop period which followed the insecticide treatment, the chlorfenvinphos soil concentrations were always greater in the organic fertilizer-treated plots, than in the untreated ones (controls). The intensity of the organic fertilizers effect as to the increase of chlorfenvinphos soil persistence was in the following increasing order: city refuse compost < cow manure < mushroom cultivation compost. The organic fertilizer effects were greater when they had been soil-incorporated 3.5 months—instead of 1 month—before the chlorfenvinphos soil treatment. The increase of the insecticide soil concentrations—due to the organic fertilizers treatments—should increase the plant protection efficiency during the period of the first 50 days, during which time the young plants are the most sensitive to insects. During the following period of the 2 or 3 last crop weeks, the effects of the organic fertilizers onto the rate of chlorfenvinphos soil metabolism were levelled off; at harvest, the very low soil-resting residues were similar in the organic fertilizers treated and untreated plots. At harvest, no chlorfenvinphos nor its metabolites were detected in the ‘flower’ of cauliflower of all the plots, the analytical limit of sensitivity being 0.02 mg kg−1 fresh weight for all of these compounds.

Effects of organic fertilizers on aldicarb soil biodegradation in sugar beet crops.

In the present work, the influences of several organic fertilizer treatment regimens were compared as to their slowing down effect on aldicarb soil metabolism in a sugar beet crop. The organic fertilizers treatment schemes had been repeatedly applied in the past 30 years, according to a 3-year rotation cycle. The following organic fertilizers treatment regimens—which are the main ones used in the agronomy practice—were compared: Treatment 1: no organic fertilizer at all; treatment 2: 40 tons cow manure ha−1; treatment 3: 40 tons pig slurry ha−1 + green manure + crop wastes; treatment 4: green manure + crop wastes; treatment 5: straw cereal wastes alone. A sugar beet crop was sown in April 1991, 1 kg aldicarb ha−1 being applied in granulates in the sowing furrow. During the 2.9 first crop months, the soil half-lives of the sum of the insecticide S- +SO- +SO2-aldicarb in the sowing line in the 0–25 cm surface soil layer were 21.6, 44.4, 39.6, 35.7, and 30.3 days in the treatments 1, 2, 3, 4, and 5 treated plots, respectively. The organic fertilizers soil treatments thus increased the persistence of the total insecticide compounds soil concentrations, and probably also the insecticide protection efficiencies. Comparison of the results obtained here with the ones previously obtained with other crop trials, herbicides and soil insecticides, suggests that the soil organic matter is the most efficient to slow down the insecticides soil biodegradation, compared to the old humus originating from the organic fertilizers treatments made more than one year ago. After the three first sugar beet crop months, the effect of the organic fertilizers treatments on the aldicarb and its insecticide metabolites soil persistences disappeared, their soil concentrations become very low and similar in the organic fertilizers treated and untreated control plots.

Chlorpyrifos Soil and Plant Metabolisms in Cauliflower Crops Grown On Cow Manure and Composts Soil Fertilized Fields

Several cauliflower crops were grown on fields located in different regions. Cauliflower plants were treated against the root fly by applying, some days after planting, chlorpyrifos onto the soil around the stem of the plant. Fields were divided into plots. Either one or 3.5 months before planting, one of the organic fertilizers city refuse compost, or mushroom cultivation compost, or cow manure was incorporated into the soil of each plot; there were also soil unamended control plots. The rates of chlorpyrifos soil metabolism were smaller in the organic fertilizers amended plots, than what they were in the unamended plots. In the summer cauliflower crop made on loamy sand soil, the chlorpyrifos soil half‐lives were 41, 44, 53 and 25 days, respectively in the plots amended either with the city refuse compost, or cow manure, or the mushroom cultivation compost, and in the unamended plots. The organic fertilizers effects were slightly greater when the amendments had been soil incorporated 3.5 months before p...

Herbicides interactions with cow manure and field soil organic matter

Abstract The direct interaction of the herbicide metazachlor ‐chosen as an example‐ with the soil organic matter has been studied by laboratory incubation of old and young cow manures containing metazachlor. The extraction efficiencies of solvents of increasing polarities indicated the formation of association compounds by bonds weaker than covalent between metazachlor and the organic matter: electron donor‐acceptor complexes, hydrogen bonding complexes, and complexes by both bonding types. Laboratory incubation of metazachlor in soil of low organic matter content indicated that the soil mineral part only had a diluting effect on the soil organic matter capacity to adsorb metazachlor. Similar association compounds were observed in the soil of a cauliflower field crop. Their concentrations were greater in the plots treated with organic fertilizers than in the organic fertilizers untreated plots. The free‐ unbound metazachlor was faster metabolized than the one bound to the soil organic matter, explaining w...

Effects of recent organic fertilizer treatment on herbicide diflufenican soil metabolism in winter wheat crops

The soil dissipation and metabolism of the herbicide diflufenican was studied in a field trial in Belgium in winter wheat which, before sowing, had been treated with green manure, cow manure, or pig slurry. Wheat was sown and the soil was treated with 250 g diflufenican ha(-1) in October. Diflufenican dissipated with first-order kinetics over the first six months with half-lives of 101, 116, 215 and 176 days in control plots, green manure, pig slurry and cow manure treated plots, respectively. The organic fertilizers soil treatments thus increased the diflufenican soil persistence, and probably also its herbicide efficiency. The organic amendments also decreased the soil concentrations of the sum of the diflufenican herbicide 2 (2-[3-(trifluoromelhyl)phenoxy]-3-pyridinecarboxylic acid) and 3 (N-(2,4-difluorophenyl)-2-hydroxy-3-pyridinecarboxamide) and non herbicide 4 (2-hydroxy-3-carbbxypyridine) metabolites. As the organic fertilizers were applied just before sowing, their effects onto the diflufenican soil metabolism corresponded to the ones of the young soil organic matter. After 6 months, the organic fertilizers effect was less pronounced leading to diflufenican (1) and its metabolites soil concentrations in all treatments becoming similarly low. The diflufenican (1) and its herbicide metabolites soil residues remaining after harvest in all the organic fertilizers treated or untreated plots would be too low to be harmful to a rotational crop.

Effects of Organic Fertilizer Treatments and Old Humus On Thiofanox and Aldicarb Soil Metabolisms in Sugar-beets

Cow manure, pig slurry, or a mixture of both were applied on field plots of a sugar beet trial, 1 month before sowing and an insecticide thiofanox soil treatment. During the first 2 months crop period, the S-+SO-+SO2-thiofanox soil half-lives were about 43 days in the organic fertilizer treated plots and 24 days in the organic fertilizer untreated control plots. In another sugar beet trial, soil was treated at sowing with the insecticide aldicarb, and the field was divided into two parts. The first part had been treated with cow manure in the autumn preceding sugar beet sowing; its organic matter concentration was 2.4%; that cow manure treatment had been repeated every 3 years for 18 years. In the second part, the soil contained a high concentration of old soil organic matter, humus (4.3%); this corresponded to a meadow ploughed 18 years ago; since then, no organic fertilizer had been applied. During the first 2 months crop period, the S-+SO-+SO2-aldicarb soil half-lives in the first and second part of the field were 63 and 29 days, respectively. The results show that the recent soil organic matter slows down insecticide soil metabolisms, and increases their protection efficiencies. However, the old soil organic matter, humus, had no significant effect on biodegradation, in spite of its high soil concentration.

Effects of the soil organic fertilizers onto the carbofuran soil and plant metabolisms in field cauliflower crops

A spring cauliflower crop was made on the loamy sand soil of a field whose plots had been amended, one month before planting, with one of the organic fertilizers: city refuse compost, or mushroom cultivation compost, or cow manure; there were also unamended control plots. Some days after planting, an emulsion of carbofuran in water was applied onto soil, around the stem of the plant, for protection against the root fly. During growth of the crop, the rates of carbofuran soil biodegradation were smaller in the organic fertilizers amended plots, than in the unamended controls; the intensity of the effect was in the increasing order: city refuse compost < cow manure < mushroom cultivation compost. The organic fertilizers thus increased the insecticide soil concentrations; they thus should increase the insecticide protection efficiency against soil insects. During the final period of the crop, the rates of carbofuran soil biodegradation increased, and the organic fertilizers effects were levelled off; at harv...