PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Humidity”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,441 records · Page 80Linked to original sources
PubMedDate not supplied

Nitrogen availability from composts for humid region perennial grass and legume-grass forage production.

Perennial forages may be ideally suited for fertilization with slow N release amendments such as composts, but difficulties in predicting N supply from composts have limited their routine use in forage production. A field study was conducted to compare the yield and protein content of a binary legume-grass forage mixture and a grass monocrop cut twice annually, when fertilized with diverse composts. In all three years from 1998-2000, timothy (Phleum pratense L.)-red clover (Trifolium pratense L.) and timothy swards were fertilized with ammonium nitrate (AN) at up to 150 and 300 kg N ha(-1) yr(-1), respectively. Organic amendments, applied at up to 600 kg N ha(-1) yr(-1) in the first two years only, included composts derived from crop residue (CSC), dairy manure (DMC), or sewage sludge (SSLC), plus liquid dairy manure (DM). Treatments DM at 150 kg N ha(-1) yr(-1) and CSC at 600 kg N ha(-1) yr(-1) produced cumulative timothy yields matching those obtained for inorganic fertilizer. Apparent nitrogen recovery (ANR) ranged from 0.65% (SSLC) to 15.1% (DMC) for composts, compared with 29.4% (DM) and 36.5% (AN). The legume component (approximately 30%) of the binary mixture acted as an effective "N buffer" maintaining forage yield and protein content consistently higher, and within a narrower range, across all treatments. Integrating compost utilization into livestock systems that use legume-grass mixtures may reduce the risk of large excesses or deficits of N, moderate against potential losses in crop yield and quality, and by accommodating lower application rates of composts, reduce soil P and K accumulation.

Animal Feed↗
PubMed2006

The effect of land use on soil health indicators in peri-urban agriculture in the humid forest zone of southern cameroon.

The objective of this study was to identify the effect of different land uses in peri-urban agriculture on the soil properties. Soil health indicators were evaluated in the top 10 cm at five tilled agricultural sites involving different cropping systems and use of agrochemicals within the peri-urban agricultural areas of Yaounde, Cameroon, and compared with a native forest land. The experimental data showed that the selected indicators were sensitive to cropping practice. Most cropped land had significantly higher total C, available N and P concentrations, soil pH, electrical conductivity, salinity, biomass C and P, dehydrogenase, beta-glucosidase, and acid phosphatase activities. Land producing corn (Zea mays L.) and sugarcane (Saccharum officinarum L.) differed from that producing tomatoes (Lycopersicon esculentum Mill.), but cultivation of these crops has significantly impacted native soil quality. However, phenol oxidase, microbal biomass C/organic C (C(mic)/C(org)), and microbial biomass C/microbial biomass P (C(mic)/P(mic)) were negatively affected. These appeared to be more consistent indicators of negative management causing changes to soil health and may be suitable for an early appraisal of soil health.

Acid Phosphatase↗
PubMed2001

Assessment of genetic variability of resistance to gastrointestinal nematode parasites in Creole goats in the humid tropics.

Goat production is widespread in the tropics. Goats are very susceptible to gastrointestinal nematode infection, but there is less evidence of their genetic resistance. Genetic resistance of Creole goats to gastrointestinal nematodes has been studied at Guadeloupe in the French West Indies since 1995. The objective of this research was to investigate genetic variation for resistance to gastrointestinal nematode infection, in order to introduce this trait into breeding schemes. Genetic variability was assessed within a Creole experimental flock. Forty-nine sire groups were characterized at weaning and 55 during fattening after weaning. Kids were naturally infected, mainly by Haemonchus contortus and Trichostrongylus colubriformis. Fecal egg counts were determined once at weaning and every 6 and 7 wk after drenching during fattening. Blood samples were collected every 7 wk during fattening for determination of packed cell volume. Live weights were recorded at weaning and at the beginning and middle of every infection period during fattening. Genetic parameters were estimated using the REML for multivariate animal models. The heritability estimate for transformed fecal egg count was 0.37+/-0.06 at weaning. During fattening, it increased from 0.14+/-0.05 at 4 mo to 0.33+/-0.06 at 10 mo. Heritabilities of packed cell volume ranged from 0.10 to 0.33. At weaning, maternal heritability of fecal egg count reached 0.26 and direct heritability 0.20. After 6 mo of age, maternal effects were found to be unimportant for fecal egg count and packed cell volume. Live weights presented significant genetic variability. Genetic relationships between fecal egg counts and live weight in infected pastures were never significant. Genetic correlations between packed cell volume and live weight decreased from 0.47 to 0.10 from weaning to 10 mo of age. These results demonstrated the feasibility of breeding for improved resistance to nematodes in Creole kids.

Animals↗