14 research outputs found
Limiting nutrients for bean production on contrasting soil types of Lake Victoria Crescent of Uganda
Common bean (Phaseolus vulgaris L.) is one of the most important grain legumes in East Africa, but its yield has remained below the genetic potential. Declining soil fertility is among the primary constraints to bean production in most East African bean producing regions. Often existing recommendations are generic and inept to guide farm level decision making on nutrient replenishment. A greenhouse nutrient omission study was conducted to determine the limiting nutrients in three soils of Masaka District, commonly cropped to beans: “Liddugavu” a Phaeozem, “Limyufumyufu” a Cambisol and “Luyinjayinga” an Umbrisol soil. Nine treatments; (i) complete nutrient treatment, (ii) N omitted, (iii) P omitted, (iv) K omitted, (v) Mg omitted, (vi) S omitted, (vii) Ca omitted, (viii) Micronutrients omitted and (ix) control without nutrients. Each treatment was randomly assigned to the three soils and replicated three times using a completely randomised design. Nitrogen, phosphorus and potassium were limiting nutrients for bean production in Umbrisol (Luyinjayinja) while in Cambisol (‘Limyufumyufu), common bean production was most limited by soil acidity. The performance varied with soil types, with beans grown on the Phaeozem registering greater leaf number and growth, confirming both scientist’s and local farmer’s knowledge that this soil has greater potential than the other two soils
Limiting nutrients for bean production on contrasting soil types of Lake Victoria Crescent of Uganda
Common bean (Phaseolus vulgaris L.) is one of the most important grain
legumes in East Africa, but its yield has remained below the genetic
potential. Declining soil fertility is among the primary constraints to
bean production in most East African bean producing regions. Often
existing recommendations are generic and inept to guide farm level
decision making on nutrient replenishment. A greenhouse nutrient
omission study was conducted to determine the limiting nutrients in
three soils of Masaka District, commonly cropped to beans:
\u201cLiddugavu\u201d a Phaeozem, \u201cLimyufumyufu\u201d a
Cambisol and \u201cLuyinjayinga\u201d an Umbrisol soil. Nine
treatments; (i) complete nutrient treatment, (ii) N omitted, (iii) P
omitted, (iv) K omitted, (v) Mg omitted, (vi) S omitted, (vii) Ca
omitted, (viii) Micronutrients omitted and (ix) control without
nutrients. Each treatment was randomly assigned to the three soils and
replicated three times using a completely randomised design. Nitrogen,
phosphorus and potassium were limiting nutrients for bean production in
Umbrisol (Luyinjayinja) while in Cambisol (\u2018Limyufumyufu), common
bean production was most limited by soil acidity. The performance
varied with soil types, with beans grown on the Phaeozem registering
greater leaf number and growth, confirming both scientist\u2019s and
local farmer\u2019s knowledge that this soil has greater potential
than the other two soils.Le haricot commun (Phaseolus vulgaris L.) est un des l\ue9gumes
\ue0 grains les plus importants en Afrique de l\u2019Est, mais son
rendement reste toujours en dessous de son potentiel
g\ue9n\ue9tique. La baisse de la fertilit\ue9 du sol est parmi
les contraintes primaires \ue0 la production du haricot dans la
plupart des r\ue9gions productrices de l\u2019Afrique de
l\u2019Est. Le plus souvent, les recommandations sont
g\ue9n\ue9riques et inad\ue9quates pour guider la prise de
d\ue9cision au niveau champ sur le r\ue9approvisionnement en
nutriment. Une \ue9tude sous serre sur l\u2019omission de nutriment
a \ue9t\ue9 conduite pour d\ue9terminer les nutriments limitants
dans les trois sols du district de Masaka, commun\ue9ment
utilis\ue9s pour produire du haricot\ua0: \u201cLiddugavu\u201d
un sol du Phaeozem, \u201cLimyufumyufu\u201d un sol du Cambisol et
\u201cLuyinjayinga\u201d un sol du Umbrisol. Neuf traitements, (i)
traitement complet de nutriments, (ii) N omis, (iii) P omis, (iv) K
omis, (v) Mg omis, (iv) S omis, (vii) Ca omis, (viii) micronutriments
omis et (ix) control sans nutriments. Chacun des traitements a
\ue9t\ue9 al\ue9atoirement distribu\ue9 aux trois types de sols
et r\ue9pliqu\ue9 trois fois dans un dispositif compl\ue8tement
al\ue9atoire. Azote, phosphore, et potassium ont \ue9t\ue9 les
nutriments limitants pour la production du haricot dans Umbrisol
(Luyinjayinja) tandis que dans Cambisol (\u2018Limyufumyufu), la
production du haricoct commun a \ue9t\ue9 limit\ue9e par
l\u2019acidit\ue9 du sol. Les performances varient en fonction des
types de sols, avec le haricot produit sur le Phaeozem comptant plus de
feuilles et de croissance, confirmant \ue0 la fois les connaissances
des scientifiques et des populations locales qui stipulent que le sol a
un potentiel plus \ue9lev\ue9 que les deux autres sols
Amelioration of sandy soils in drought stricken areas through use of Ca-bentonite
Soil moisture shortage is a major limiting factor to agricultural production in eastern Africa, in view of increased drought incidences and seasonal rainfall variability. This study evaluated the potential for Ca-bentonite (a 2:1 clay mineral) as a possible amendment for increased moisture retention by sandy soils in drought stricken/prone areas in Uganda. The study was conducted both in the greenhouse at NARL-Kawanda and in the field, Nakasongola district. In the greenhouse (27-30oC), Ca-bentonite was mixed with a sandy soil in proportions of 0, 5, 10, 15 and 20% by weight, replicated three times. The mixtures were watered to field capacity (30% water) then maize (Longe V) planted and left to grow for 5 weeks without any additional water application. Under field conditions, Ca-bentonite was applied on sandy soils in the drought-prone Lwabiyata sub county, Nakasongola district in central Uganda. Treatments included: Ca-bentonite applied at 0, 1.25 and 2.5 t ha-1; DAP at 0, 62.5 and 125 kg ha-1; urea at 0 and 60 kg ha-1; and farmyard manure (FYM) at 0, 1.25 and 2.5 t ha-1, arranged in a randomised block design with three replicates. Under greenhouse conditions, Ca-bentonite application significantly (P<0.05) increased the soil moisture retention, pH, N, P, Ca and Mg content, and subsequently, maize dry matter yield. Averaged over 2 seasons, field application of 2.5 t Ca-bentonite ha-1 increased maize grain yield by 37.6%. Yields were significantly (P<0.05) higher (79.8 to 82.0% above the control) where bentonite (2.5 t ha-1) was combined with DAP (62.5 kgha-1 or FYM (2.5 tha-1). The results suggest that Cabentonite has potential as a soil amendment for moisture conservation, neutralising acidity, and improving N, P, Ca and Mg content in sandy soils, and consequently support crop growth and yield. Thus calcium bentonite presents a possible amelioration for sandy soils of low fertility in drought stressed environments. It is thus a promising technology for climate change adaptation in drought prone areas.Keywords: Climate change adaptation, drought mitigation, moisture stress, soil moisture conservation, soil fertility managemen
Non-point Source Pollution into Lake Victoria from Bukora, Uganda Sub-catchment
Non-point source pollution from agricultural land is a major contributor of N, P and sediments resulting into eutrophication and siltation of water bodies. The extent of this pollution is accelerated by poor land management practices that lead to extensive soil erosion. PoUutant concentrations and loads from two micro-catchments of Bukora sub-catchment. a predominantly agro-pastoral area of Rakai district. were studied over a three-year period. The two microcatchments are drained by two rivers. which eventually discharge into Lake Victoria. Three hydrological stations were constructed onto the two rivers and water sampling and river discharge measurement routine is carried out. During the study period, highest rain fall amounts were recorded in April, while peak river discharge (Oow rate) occurred during July, signifying a 3-months ground recharge period. Concentrations and loads of Total N (TN) and Total P (TP) were related to Total Suspended Solids (TSS) indicating the contribution of N and P-rich sediments toN and P loading. Seasonal trends in TSS, TP and TN concentrations and loads were closely related to river discharge. Mean annual concentrations for TN ranged from 3.2 to 10.4 mg L-1 with loads of 40 to 70 ton yr-1. Annual means for TP ranged from 0.2 to 0.4 rng L-1 wilh loads of 4 to 51 ton y-1, while TSS ranged from 12 to 94 mg L-1 with loads of 2 to 40 ton yr-1. Concentrations and loads ofTSS, TN and TP were reduced across a wetland, especially during periods of low flow. High sediment, N and P pollutant concentrations and loads are likely a result of extensive soil erosion in the area_ Results call for promotion or better land management practices so as to reduce non-point pollution of rivers and consequently. lake Victoria.Keywords: Eutrophication, Water quality. Watershed management. Wetlands
An integrated approach to sustainable utilisation of land resources for a better environment
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