Effects of some organophosphate and carbamate insecticides on nitrification and legume growth

Influence of four pesticide formulations on microbial processes in a New Zealand pasture soil

“…Tu (1970) found that four organophosphates, at concentrations of 10 and 100 ppm, mostly increased the production of NH4,-N from soil organic matter, but slightly depressed its oxidation to NOa-N; in contrast, low concentrations of fensulfothion slightly stimulated the production of NOa-N (Tu 1972). Bartha et al (1967) and Lin et al (1972) also noted a depression in the production of NOaN from added NH4,-N in the presence of large amounts of several organophosphate pesticides. On the other hand, increased production of NOa-N in a volcanic ash soil following a high rate of application of disulfoton (diethyl S-[2-(ethylthio) ethyl] phosphorothiolothionate) was observed by Kobayashi & Katsura (1968).…”

“…Although Ball (1966) has shown that some grass species can grow as well with NH4,-N as with NOa-N, further experiments are desirable to determine whether the growth of other pasture species, or of other crops, could be influenced by the NH4,-N that might accumulate after heavy applications of this pesticide. Tu (1972) found that 5 ppm carbofuran slightly stimulated nitrification, whereas Lin et al, (1972) found that 500 ppm had no effect on soil in laboratory experiments.…”

“…On the other hand, some plants appear to prefer NH4-N (Goring 1970); compounds that inhibit the conversion of NH4-N to N03-N may also be desirable under some field conditions to prevent losses of N03-N through leaching or denitrification. Some pesticides, at high concentrations, may also influence the nitrogen cycle through their toxicity to nitrogen-fixing organisms and pasture legumes (Alexander 1969;Audus 1970;Helling et al 1971;Lin et al, 1972).…”

Effect of the Insecticide Carbofuran on Microbial Activities in Flooded Soil

“…wrnc observed at 5C.15.6) In separate studies by Hubbel et al 6) and Lin et al. 9' carbofuran applied at field rates showed no effect on nitrification in a loamy fine soil. Ramakrishna et al 11) showed that a concentration as high as 0.5% could lead to an accumulation of N02-due to a selective inhibition of N02-oxidation combined with a slight stimulatory effect on NH4+-oxidation in flooded soil.…”

Interaction of three Iowa surface soils with the organophosphorus insecticide Counter®

“…It was found again that the ability of these insecticides to retard nitrification decreased with time, nubbell et al (1973) reported parathion at 2 ppm reduced nitri fication by about 25% during the first 8 weeks. Lin et al (1972) studied the effect of 6 organophosphorus insectici des (trichlorfon, Dyfonate , Bayer 37,289, carbophenothion, chlorpyrifos, and Nemacur-P ) and 3 carbamates (propoxur, aldicarb, and carbofuran) on soil nitrification. No inhibition was found at normal field rates (5 ppm) of application.…”