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Study of agronomic activities at the Kalimbeza rice project Namibia and the implication for sustainable productivity of the rice soil

By: V. Hepute, J. Abah

Key Words: Rice soil, Agronomic activities, Sustainability, Kalimbeza

Int. J. Biosci. 10(5), 128-138, May 2017.



In order to design sustainable management of the Kalimbeza rice project soil, it is expedient to assess the sustainability implication of the current agronomic activities which has the potential to threaten long term productivity of the rice soils. First, structured questionnaires were used to collect data from 10 field workers based on their memory recall of the different agronomic activities carried out at the rice project. Furthermore, soil samples were collected from the Kalimbeza rice soil at two depths: 0-15cm and 15-30cm for analyses of the soil properties. A fallow land of more than 10 years was also sampled at the same soil depths and analysed as control. The results obtained from the questionnaires responses revealed that chemical fertilizers are frequently used to improve the rice soil fertility but the fertilizers were applied without prior soil analysis to ascertain the nutrients status. It was also revealed that rice mono-cropping system is solely practiced, coupled with maximum harvesting as rice residues were used to produce livestock feed and not left to decay into the soil. T-test (paired sample mean, p < 0.05) analysis of the soil properties revealed that the rice soil has significantly lower levels of: total nitrogen, phosphorus, organic carbon, and cation exchange capacity than the control soil. Rice mono-cropping and maximum harvesting practiced at the Kalimbeza rice project could affect recovery capacity of the rice soil and present adverse implications for its sustainable productivity over long period. Therefore, it is recommended that crop rotation, leaving rice residues to decay and improve the soil structure, and applying chemical fertilizers after pre-determined site-specific properties should form part of the agronomic activities.

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Study of agronomic activities at the Kalimbeza rice project Namibia and the implication for sustainable productivity of the rice soil

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V. Hepute, J. Abah.
Study of agronomic activities at the Kalimbeza rice project Namibia and the implication for sustainable productivity of the rice soil.
Int. J. Biosci. 10(5), 128-138, May 2017.
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