ENHANCING RESPONSE FARMING FOR STRATEGIC AND TACTICAL MANAGEMENT OF RISKS OF SEASONAL RAINFALL VARIABILITY

Seasonal rainfall variability, particularly the uncertainty with respect to the direction and extent that variability will assume in a given season, forms the greatest source of risk to crop production in semi-arid areas of Ethiopia. Equipping vulnerable communities, in advance, with the expected date of onset of a cropping season, is crucial for smallholder farmers to better prepare to respond and manage the uncertainties. Therefore, rainfall prediction, particularly development of models that can foretell the date of onset of next cropping season is crucial in facilitating strategic agronomic planning and tactical management of in-season risks. A twenty-four-year climatic data study was conducted for Melkassa Agricultural Research Centre (MARC) in semi arid Ethiopia, to develop onset date prediction models that can improve strategic and tactical response farming (RF). A sequential simulation model for a build up of 15 to 25 mm soil water by April 1st, was conducted. Simulation results revealed a build up of soil water up to 25 mm, to be the most risk-wise acceptable time of season onset for planting of a 150-day maize crop. In the context of response farming, this was desirable as it offers the opportunity for farmers to consider flexible combination production of maize ( Zea mays L.) varieties of 120 and 90 days in the event of failure of earliest sown 150-day maize crop. Thus, to allow for flexible combination production of the three maize varieties, predictive capacity was found crucial for April onset of the next crop season. Accordingly, based on the consideration of pre-onset rainfall parameters, the first effective rainfall date varied considerably with the date of onset of rainfall. Regression analyses revealed the first effective rainfall date to be the best predictor of the date of onset (R2 = 62.5%), and a good indicator of the duration of next season (R2 = 42.4%). The identified strategic predictor, the first effective rainfall date, enabled prediction of time of season onset and season length by a lead time of two to three months. This markedly improved Stewart\u2019s RF. The date of onset of the next crop season was also found to be a useful predictor of season duration (R2 = 87.3%). Strategic agronomic planning should be adjusted according to the first effective rain date, and tactically according to what date of rainfall onset informs us about expectations in the duration and total season water supply.La variabilit\ue9 saisonni\ue8re de la pluviom\ue9trie, particuli\ue8rement l\u2019incertitude en rapport avec la direction et l\u2019ampleur de cette variabilit\ue9 au cours d\u2019une saison donn\ue9e est un grand risque \ue0 la production agricole dans les zones semi- arides de\ua0l\u2019Ethiopie. La provision \ue0 l\u2019avance d\u2019information sur les dates correspondantes aux d\ue9buts des saisond culturales s\u2019av\ue8re cruciale pour que les communaut\ue9s dans des zones vuln\ue9rables puissent g\ue9rer les risques li\ue9s \ue0 la variabilit\ue9 saisoni\ue8re de la pluviom\ue9trie Par cons\ue9quent, la pr\ue9diction de la pluviom\ue9trie, en particulier le d\ue9veloppement des mod\ue8les pouvant pr\ue9voir \ue0 l\u2019avance la date du d\ue9but de la prochaine saison culturale est cruciale pour faciliter une planification strat\ue9gique de la saison culturale et une gestion tactique des risques au cours de la saison culturale. Une \ue9tude des donn\ue9es climatiques de vingt quatre ann\ue9es \ue9tait men\ue9e au Centre de Recherche Agricole de Melkassa situ\ue9 dans la zone semi-aride de l\u2019Ethiopie afin de d\ue9velopper des mod\ue8les de pr\ue9diction des d\ue9buts de saisons culturales pouvant am\ue9liorer la r\ue9ponse strat\ue9gique et tactique aucours des saisons culturales. Un mod\ue8le de simulation s\ue9quentiel pour une accumulation de 15 \ue0 25 mm d\u2019eau dans le sol au 1er Avril \ue9tait d\ue9velopp\ue9. Les r\ue9sultats de cette simulation ont r\ue9v\ue9l\ue9 qu\u2019une accumulation de 25mm d\u2019eau dans le sol constitue le niveau de risque le plus acceptable pour le d\ue9but de la saison culturale et le semis d\u2019une culture de ma\uefs \ue0 maturit\ue9 de 150 jours. Dans le contexte de d\ue9velopper une agriculture adapt\ue9e aux variabilit\ue9s saisonni\ue8res, cette strrat\ue9gie est appropri\ue9e car elle offre aux agriculteurs une opportunit\ue9 d\u2019\ueatre flexible et d\u2019envisager de semer des combinaisons de 3 vari\ue9tes de ma\uees pouvant inclure des vari\ue9t\ue9s \ue0 90, 120 et 150 jours de maturation pour s\u2019assurer d\u2019avoir une r\ue9colte satisfaisante en cas d\u2019\ue9chec de la vari\ue9t\ue9 \ue0 150 jours. Ainsi, pour permettre une combinaison flexible de production de ces trois vari\ue9t\ue9s de ma\uefs, la capacit\ue9 de pr\ue9dire le d\ue9but de la prochaine la saison culturale d\u2019Avril \ue9tait jug\ue9e cruciale. Par cons\ue9quent, sur base des param\ue8tres pr\ue9-pluviom\ue9triques, la date de la premi\ue8re pluie diff\ue9rait consid\ue9rablement avec la date effective du d\ue9but de la saison des pluies. Les analyses de r\ue9gression ont r\ue9v\ue9l\ue9 cependant que la date de la premi\ue8re pluie est le meilleur pr\ue9dicateur de la date du d\ue9but de la saison culturale (R2=62.5), et un bon indicateur de la dur\ue9e de la prochaine saison culturale (R2=42.4%). L\u2019indicateur strat\ue9gique identifi\ue9e qu\u2019est la date de la premi\ue8re pluie permet de pr\ue9dire la date effective du d\ue9but de la saison culturale et de la longueur de la saison culturale 2 \ue0 3 mois \ue0 l\u2019avance. Ceci a am\ue9lior\ue9 remaquablement le mod\ue8le d\u2019adaptation de la saison culturale \ue0 la variabilit\ue9 climatique de Steward (mod\ue8le RF de Steward). La date du d\ue9but de la prochaine saison culturale s\u2019est aussi av\ue9r\ue9 \ueatre un pr\ue9dicateur utile de la dur\ue9e de saison culturale (R2=87.3%). Cette \ue9tude montre que la planification strat\ue9qique de la saison culturale devrait \ueatre ajust\ue9e sur base de la date de la premi\ue8re pluie, et tactiquement, ajust\ue9e sur base des informations que la date effective du d\ue9but de la saison des pluies donne en rapport avec la dur\ue9e de la saison et la pluviom\ue9trie totale au cours de la saison

IMPACT OF PROJECTED CLIMATE CHANGE ON AGRICULTURAL PRODUCTION IN SEMI-ARID AREAS OF TANZANIA: A CASE OF SAME DISTRICT

Sub-Saharan Africa is one of the most vulnerable regions in the World to climate change because of widespread poverty and limited adaptive capacity. The future climate change is likely to present an additional challenge to the agricultural sector. Therefore, the effects of climate change on the current agronomic management practices were investigated using Same District, Tanzania as a case study area. APSIM software was used to investigate the response of maize ( Zea mays ) yield to different agronomic management practices using current and future (2046 - 2065) climate data. The climate change projections data from global climate models were downscaled using self-organising maps technique. Under the conventional practices, results show that during long rainy season (from March to May) there is yield decline of 13% for cultivar Situka, no change for cultivar Kito and increase of 10% and 15% for cultivars Sc401 and TMV1, respectively. Under the recommended practices, cultivars TMV1 and Sc401 are projected to register a 10% yield increase whereas cultivars Situka and Kito are projected to register a decrease of 10% and 45%, respectively. Also, under both conventional and recommended management practices, results showed that during short rainy season (from october to December/January) all cultivars are projected to register between 75% and 146% increase in maize yields. This implies that future climate change is going to have positive effects on current management practices during short rainy seasons and it will have negligible impact during long rainy seasons.L\u2019Afrique subsaharienne est une des r\ue9gions plus vuln\ue9rables au changement climatique au monde suite \ue0 la pauvret\ue9 g\ue9n\ue9ralis\ue9e et la capacit\ue9 d\u2019adaptation limit\ue9e. Dans l\u2019avenir, le changement climatique pr\ue9sentera probablement des d\ue9fis additionnels au secteur agricole. Pour ce faire, les effets du changement climatique sur les pratiques courantes de gestion agronomiques \ue9taient \ue9tudi\ue9s dans le district de Same en Tanzanie. Le logiciel APSIM \ue9tait utilis\ue9 en exploitant les donn\ue9es climatiques actuelles et futures (2046-2065), afin d\u2019\ue9valuer les effets des diff\ue9rentes pratiques agronomiques de gestion sur le rendement du ma\uefs ( Zea mays ). La projection des donn\ue9es de changement climatique \ue0 partir des mod\ue8les climatiques au niveau plan\ue9taire a \ue9t\ue9 r\ue9duite \ue0 l\u2019\ue9chelle \ue0 l\u2019aide de la technique d\u2019auto-organisation des cartes. Sous les pratiques conventionnelles, les r\ue9sultats montrent que durant la longue saison de pluie (du Mars au Mai) il ya eu diminution de 13% du rendement du cultivar Situka, augmentation 10% et 15% du rendement des cultivars Sc401 et TMV1, respectivement. Le cultivar Kito n\u2019a connu aucun changement de rendement. Sous les pratiques recommand\ue9es, les projections montrent que les cultivars TMV1 et Sc401 connaitront une augmentation de 10% de rendement pendant que les cultivars Situka et Kito enregistreront une baisse de rendement de 10% et 45%, respectivement. Aussi, sous les deux pratiques de gestion conventionnelles et recommand\ue9es, les r\ue9sultats de projections montrent que durant la courte saison de pluie (d\u2019octobre \ue0 D\ue9cembre/Janvier) tous les cultivars enregistreront une augmentation de rendements d\u2019entre 75% et 146%. Ceci impliquent des effets positifs du future changement climatique sur les pratiques courantes de gestion durant la courte saison de pluie et un effet n\ue9gligeable pendant la longue saison pluvieuse

Silicon status in soil and its effect on growth and yield of rice under the system of rice intensification and continuous flooding in Mkindo Irrigation Scheme, Morogoro, Tanzania

Silicon (Si) improves physical, chemical and biological properties of soil, enhances growth and rice yield. Hence, Si deficiency in the soil may lead to decline in rice yields. A study was undertaken to assess Si status in soils and its relation to growth and yield parameters of rice plant grown under the system of rice intensification (SRI) and continuous flooding regime in Mkindo Irrigation Scheme, Morogoro, Tanzania. A randomized complete block design (RCBD) with two treatments replicated three times was employed for the experiment. The treatments were two water application regimes (T1 and T2). T1 was alternate wetting and drying using SRI technology and T2 was continuous flooding. Rice variety SARO 5 (TXD 306) was used as a test crop. The experiment was conducted for two consecutive seasons from October 2019 to January 2020 and from March 2020 to June 2020. The objectives of the study were to assess the Si status in soils of the experimental site and to examine growth (in terms of plant height, number of tillers, number of productive tillers and number of panicles per hill) and grain yield in relation to soil Si status. Results showed that the soils of the study area had sufficient amount of available Si content (235.5 mg kg-1). Plots under SRI technology recorded higher plant height (147 cm), number of tillers per hill (54), number of productive tillers per hill (46), number of panicles per hill (31) and grain yield (8 tons ha-1). On the other hand plots under continuous flooding gave lower plant height (129 cm), number of tillers per hill (27), number of productive tillers per hill (22), number of panicles per hill (27) and grain yield (3 tons ha-1). It was thus concluded that, SRI enhanced higher uptake of soil Si which in turn improved significantly crop growth and rice yield

Influence of irrigation water quality on soil salinization in semi-arid areas: a case study of Makutopora, Dodoma-Tanzania

Article published in a journal titled: International Journal of Scientific & Engineering Research, Volume 6, Issue 9, September-2015This research was carried out in Dodoma, at Makutopora Agricultural Research Institute. The main objective was to determine the influence of irrigation water on soil salinization in semi-arid areas. A total of 80 representative soil samples were randomly collected from study area. Two water samples were also collected from the study area. The samples were treated and analyzed for physical and chemical related indices. The results are grouped into general quality parameters, which included salinity and salt inducing cations and anions. The findings indicated that the mean pH was 7.53 while the mean EC value was 944.5 μS/cm. The mean cations in the water were 3.97, 4.32, 2.57, and 11.39 meq/l for Ca2+, Mg2+, K+, and Na+, respectively. The Sodium Adsorption Ratio (SAR) was 5.60. The mean carbonates concentration detected in the irrigation water was 9.05 meq/l, while the mean chloride and sulfide were 17.20 and 3.6 meq/l, respectively. Soil samples were grouped into three major groups namely non-irrigated, half irrigated, and full irrigated soils. For the non-irrigated, half irrigated, and full irrigated soils: the mean pH in the soil was 6.59, 6.89 and 7.04, respectively; the mean ECe were 94.35, 338.5, and 344.72, mS/cm, respectively; SAR was 0.76, 2.64, and 4.82, respectively; exchangeable cations and anions as shown in Table 4, 6 and 8. The results reveal that water may have the potential to be hazardous to the soil as well as to the crop grown because most parameters were above safe limits. The linear regression model showed high correlation of soil salinity with exchangeable bases with R2 =0.776 and significant at p≤0.04 for non-irrigated soil, R2=0.627 at p≤0.001 for half irrigated soil, and R2=0.597 at p≤0.003 for full irrigated soil. For all soil samples the linear regression model shows strong relationships that exist between the soil salinity and exchangeable bases present in the soil. It is recommended that adequate drainage with emphasis on surface drainage should be provided and salt and sodium build up should be monitored regularlyTrans-SEC-Projec

Evaluation of water productivity for maize under drip irrigation

A drip system operating under deficit irrigation was used to evaluate water productivity (WP) of TMV-1 maize variety in Morogoro, Tanzania. A block was divided into four sub-blocks; and each randomly assigned with deficit treatment (T1, T2, T3 and T4 as 60%, 40%, 20% and 0% irrigation water deficits, respectively). Three replications were used producing randomized block design. Each sub block biomass, grain yield and harvest index were determined. Biomass development and grain yield were significantly (0.1<P<0.05) influenced by water deficit. Both increased with increasing irrigation water to full irrigation. WP were different (P=0.1), with T2 having the highest value (2.2 kg/m3)

Agricultural water management in a water stressed catchment: lessons from the RIPARWIN Project

In the face of growing water stress and increasing concerns over the sustainability of water use, Tanzania has, in common with many other countries in Africa, focused largely on the development of more integrated catchment-wide approaches to water management. In the Great Ruaha River Basin, considerable effort has gone into increasing water productivity and the promotion of mechanisms for more efficient allocation of water resources. Over a period of five years, the RIPARWIN project investigated water management in the basin and evaluated the effectiveness of some of the mechanisms that have been introduced. The study findings are relevant to basins in developing countries where there is competition for water and irrigation is one of the main uses

The adequacy of Off-farm coping strategies in reducing livelihood risks associated with climate variability in dry-land farming areas

The impacts of climate variability and change on the agricultural sector are projected to steadily manifest through changes in land and water regimes. All together affects crop production eventually affects livelihoods. There are varieties of measures that have been taken so far to cope with the situation, off-farm activities being one of the strategies. Therefore, this paper assess as the adequacy of off-farm coping strategies in reducing livelihood risks associated with climate variability. Data were collected from a sample of 150 farming households via questionnaire survey, in five villages located in the upland, midland and lowland areas of Same district of Northern Tanzania along the Pangani river basin. Multistage analysis was used for descriptive and quantitative data analyses. Findings revealed that crop production was low compared to household food needs during 2008/2009 agricultural season. None of the zones managed to produce enough food to sustain entire household for the whole season. Therefore, evidently findings had shown the importance of off¬-farm activities in rescuing farmers during various shocks, especially when there is crop failure. Sell of livestock and livestock products; small businesses; labour intensive activities; as well as transfer payments were the major off-farm activities used by farmers to supplement the household food and income due to crop failure in the 2008/2009 agricultural season. However, farmers were advised to do most of the off-farm activities which have comparatively high returns with fewer risks.Institute of Rural Development Planning; Soil Water Management Research Group (SWMRG) Sokoine University of Agricultur

Influence of irrigation water quality on soil salinization in semi-arid areas: A case study of Makutopora, Dodoma-Tanzania

International Journal of Scientific & Engineering Research, 2015; 6(9): 1435-1446This research was carried out in Dodoma, at Makutopora Agricultural Research Institute. The main objective was to determine the influence of irrigation water on soil salinization in semi-arid areas. A total of 80 representative soil samples were randomly collected from study area. Two water samples were also collected from the study area. The samples were treated and analyzed for physical and chemical related indices. The results are grouped into general quality parameters, which included salinity and salt inducing cations and anions. The findings indicated that the mean pH was 7.53 while the mean EC value was 944.5 µS/cm. The mean cations in the water were 3.97, 4.32, 2.57, and 11.39 meq/l for Ca2+, Mg2+, K+, and Na+, respectively. The Sodium Adsorption Ratio (SAR) was 5.60. The mean carbonates concentration detected in the irrigation water was 9.05 meq/l, while the mean chloride and sulfide were 17.20 and 3.6 meq/l, respectively. Soil samples were grouped into three major groups namely non-irrigated, half irrigated, and full irrigated soils. For the nonirrigated, half irrigated, and full irrigated soils: the mean pH in the soil was 6.59, 6.89 and 7.04, respectively; the mean ECe were 94.35, 338.5, and 344.72, mS/cm, respectively; SAR was 0.76, 2.64, and 4.82, respectively; exchangeable cations and anions as shown in Table 4, 6 and 8. The results reveal that water may have the potential to be hazardous to the soil as well as to the crop grown because most parameters were above safe limits. The linear regression model showed high correlation of soil salinity with exchangeable bases with R2 =0.776 and significant at p≤0.04 for non-irrigated soil, R2=0.627 at p≤0.001 for half irrigated soil, and R2=0.597 at p≤0.003 for full irrigated soil. For all soil samples the linear regression model shows strong relationships that exist between the soil salinity and exchangeable bases present in the soil. It is recommended that adequate drainage with emphasis on surface drainage should be provided and salt and sodium build up should be monitored regularly

Influence of irrigation water quality on soil salinization in semi-arid areas: a case study of Makutopora, Dodoma-Tanzania

Article published in a journal titled: International Journal of Scientific & Engineering Research, Volume 6, Issue 9, September-2015This research was carried out in Dodoma, at Makutopora Agricultural Research Institute. The main objective was to determine the influence of irrigation water on soil salinization in semi-arid areas. A total of 80 representative soil samples were randomly collected from study area. Two water samples were also collected from the study area. The samples were treated and analyzed for physical and chemical related indices. The results are grouped into general quality parameters, which included salinity and salt inducing cations and anions. The findings indicated that the mean pH was 7.53 while the mean EC value was 944.5 μS/cm. The mean cations in the water were 3.97, 4.32, 2.57, and 11.39 meq/l for Ca2+, Mg2+, K+, and Na+, respectively. The Sodium Adsorption Ratio (SAR) was 5.60. The mean carbonates concentration detected in the irrigation water was 9.05 meq/l, while the mean chloride and sulfide were 17.20 and 3.6 meq/l, respectively. Soil samples were grouped into three major groups namely non-irrigated, half irrigated, and full irrigated soils. For the non-irrigated, half irrigated, and full irrigated soils: the mean pH in the soil was 6.59, 6.89 and 7.04, respectively; the mean ECe were 94.35, 338.5, and 344.72, mS/cm, respectively; SAR was 0.76, 2.64, and 4.82, respectively; exchangeable cations and anions as shown in Table 4, 6 and 8. The results reveal that water may have the potential to be hazardous to the soil as well as to the crop grown because most parameters were above safe limits. The linear regression model showed high correlation of soil salinity with exchangeable bases with R2 =0.776 and significant at p≤0.04 for non-irrigated soil, R2=0.627 at p≤0.001 for half irrigated soil, and R2=0.597 at p≤0.003 for full irrigated soil. For all soil samples the linear regression model shows strong relationships that exist between the soil salinity and exchangeable bases present in the soil. It is recommended that adequate drainage with emphasis on surface drainage should be provided and salt and sodium build up should be monitored regularlyTrans-SEC-Projec