EFFECTS OF WATER HARVESTING AND FERTILISER ON YIELD AND WATER USE EFFICIENCY OF SORGHUM IN SEMI-ARID EASTERN KENYA
Abstract
Sorghum (Sorghum bicolor) is the second most important cereal crop in semi-arid eastern Kenya after maize. Its production is constrained by low soil water status and nutrient deficiencies, particularly, nitrogen and phosphorus.
Despite the low and erratic rainfall received in these areas, runoff is a conspicuous feature of many rainfall events (Imbira, 1989), and has been observed from a rainfall event of as low as 7.8 mm (Critchely, 1989). This runoff can be collected and impounded in the cultivated/cropped area, thereby increasing the availability of water to crops. The source of runoff (catchment) can be either external (macro-catchment) or within the cultivated area (micro-catchment). Improving soil water status through these techniques, referred to as rainwater/runoff harvesting, has been shown to significantly increase sorghum yields in semi-arid areas of Kenya (Imbira, 1989; Critchely, 1989; Gibberd, 1993). Similarly, alleviation of nutrient deficiencies in these areas, through application of chemical fertilisers, has been shown to have a similar effect on sorghum yields (Whiteman, 1981; Okalebo et al., 1989; Okalebo et al., 1990).
In the semi-arid regions of West Africa, it has been reported that application of fertilisers result in increased water use efficiency (WUE) of sorghum (Onken et al., 1990). A combination of agronomic practices that lead to increased availability of water to a sorghum crop and an improvement in the nutrient status of the soil are, therefore, essential for maximisation of sorghum yields in semi-arid environments.
This paper reports the results of a study conducted on a subsistence farm in semi-arid eastern Kenya to determine the response of sorghum to two water harvesting techniques at low and optimum fertility levels.
Copyright Notices
1. Policy for Journals That Offer Open Access
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
Proposed Policy for Journals That Offer Delayed Open Access
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication, with the work [SPECIFY PERIOD OF TIME] after publication simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
