| dc.description.abstract | A rice (Oryza sativa L.) crop functions as a population of tillers produced at different times and possessing specific growth characteristics not as a homogeneous population of plants. The objective of this study was to characterise the growth, yield-variables and cultural practices of upland rice in relation to biophysical factors among smallholder farmers. Farmers in Namalemba sub-county in Iganga district were interviewed for willingness and appropriateness to participate in the cross-sectional study. Twelve rice fields of variety Nerica 4 at the early vegetative phase (21–30 days after sowing) from three landscape positions categorized as upper, middle and lower were surveyed in October 2022. Fields were characterized for biophysical factors including slope, soils and altitude. Soil samples were taken, plant height, plant population, tiller number and root biomass were measured from three sampling units in each field. Farmers were interviewed within their fields for information on cultural practices including spacing, sowing date, cultivation methods, sowing method, seed rate which were verified by observations. Plant densities increased in a clear pattern moving from the upper, mid- to the lower slope positions. The trend in plant densities with landscape positions were attributed to difference in distribution and types of soils due to clay composition. Rice fields located at places of high clay contents (> 40%) in the lower slopes had high plant densities and farmer’s expected high yields. There was a relationship (R2 = 96.5) between plant densities and clay content indicating that the role of clay fraction on soil water retention. The majority of the rice fields were established using broadcasting. However, it was notable that in Namalowe and Namalemba village, farmers used improved sowing methods. Sowing methods thus had a strong influence on tiller densities at vegetative stage with 1266.3 tillers ha-1 in broadcast, compared to 566.7 ha-1 for dibble and 244.4 ha-1 for drill. As farmers generally used low seed rates notably for the fields on the upper slopes, they should raise seed rates by approximately 30 kg ha-1. There is need to however establish appropriate plant densities for optimal yields on farmers’ fields that use no fertilizers and different sowing methods.
Key words: Landscape positions, Nerica 4, sowing methods, seed rates | en_US |
