Farmyard manure application in weathered upland soils of Madagascar sharply increase phosphate fertilizer use efficiency for upland rice

Potassium Supplying Capacity and High Efficiency Use of Potassium Fertilizer in Upland Soils of Hunan Province (China)

Upland Rice and Allelopathy

Upland rice (Oryza sativa L.) is mainly grown in Asia, Africa and Latin America. Yield potential of upland rice is quite low and invariably this crop is subjected to many environmental stresses. Further, when upland rice is grown in monoculture for more than two to three years on the same land, allelopathy or autotoxicity is frequently reported. Allelopathy involves complex plant and plant chem...

Response of traditional and improved upland rice cultivars to N and P fertilizer in northern Laos

Upland rice is typically grown under slash-and-burn systems in the mountainous regions of northern Laos by resource-poor farmers for subsistence. Upland rice cultivars are all traditional and no fertilizer inputs are used. In these systems, grain yields average only 1.7 t/ha. A multi-site experiment was conducted in Luang Prabang province to examine cultivar and fertilizer effects on grain yiel...

Herbicidal Activity and Residual States of Metolachlor in Upland Soils

The residues of metolachlor [2chloro-2'-ethyl-N-(2-methoxy-l-methylethyl)6'-methylacetanilide] applied to a soybean field were determined separately as to water-soluble and water-insoluble ingredients and were found to fluctuate with precipitation. The half life of all metolachlor was calculated as 40 to 60 days in 1990 and 4 to 5 days in 1991. The half life of the water-soluble ingredients, ho...

Direct and residual phosphorus effects on grain yieldphosphorus uptake relationships in upland rice on an ultisol in West Africa

Phosphorus (P) deficiency is a major constraint to crop production on highly weathered, lowactivity clay soils in the humid zone of West Africa. Past research suggested a linear relationship between grain yield and P uptake over a range of fertilizer P applied to upland rice cultivars. However, there is lack of information on how these relationships are affected by the long-term fertilizer ...