EFFECT OF RIDGING AND INTERCROPPING ON SORGHUM PRODUCTIVITY IN ARID AND SEMI-ARID LANDS OF EASTERN KENYA

Soil moisture deficit is a key constraint to sorghum ( Sorghum bicolor ) productivity in arid and semi-arid lands globally. The objective of this study was to determine the effect of ridging and sorghum-bean intercropping (additive system) on soil moisture conservation and sorghum productivity. Sorghum (gadam) was grown either as a sole crop or intercropped with two bean ( Phaseolus vulgaris L.) varieties (KATx56 and KAT B1), under two types of ridging (open ridges and tied ridges), and a control without ridges for two years. The study was set up in split plot arrangement, in a randomised complete block design, at the Kenya Agricultural and Livestock Research Organization, Kiboko, in 2019 and 2020. There was no significant interaction between ridging and intercropping. Soil moisture content increased by 11-26% due to ridging; and decreased by -11 and -7% due to sorghum-KAT B1 and Sorghum-KAT X56 intercropping, respectively. Higher moisture content due to ridging was attributed to formation of basin-like structures, which increased water harvesting and infiltration compared to the no ridges where surface run-off was predominant. The highest moisture content was attained on sole bean, followed by sole sorghum and then sorghum/bean intercropping. The decrease in moisture content in intercrops of sorghum/bean relative to their specific sole crops was attributed to higher crop density, which reduced crop spacing, thus triggering competition for available soil moisture. The highest sorghum grain and equivalent yields were obtained in the ridged plots. Intercropping resulted into decrease in sorghum grain yield, but led to increase in sorghum equivalent yield (SEY) and Land Equivalent Ratio (LER). The results show that both ridging and intercropping are suitable for higher water use efficiency and land productivity in ASALs of Kenya.Le d\ue9ficit d\u2019humidit\ue9 du sol est une contrainte majeure \ue0 la productivit\ue9 du sorgho (Sorghum bicolor) dans les terres arides et semi-arides \ue0 l\u2019\ue9chelle mondiale. L\u2019objectif de cette \ue9tude \ue9tait de d\ue9terminer l\u2019effet du billonnage et de la culture intercalaire sorgho-haricot (syst\ue8me additif) sur la conservation de l\u2019humidit\ue9 du sol et la productivit\ue9 du sorgho. Le sorgho (gadam) \ue9tait cultiv\ue9 soit en monoculture, soit en association avec deux vari\ue9t\ue9s de haricot (Phaseolus vulgaris L.) (KATx56 et KAT B1), sous deux types de billons (billons ouverts et billons li\ue9s), et un t\ue9moin sans billons pendant deux ann\ue9es. L\u2019\ue9tude a \ue9t\ue9 mise en place en parcelles divis\ue9es, dans une conception en blocs complets randomis\ue9s, \ue0 l\u2019Organisation de recherche sur l\u2019agriculture et l\u2019\ue9levage du Kenya, Kiboko, en 2019 et 2020. L\u2019\ue9tude n\u2019a montr\ue9 aucune interaction significative entre le billonnage et la culture intercalaire. La teneur en humidit\ue9 du sol a augment\ue9 de 11 \ue0 26 % en raison du billonnage ; et diminu\ue9 de -11 et -7% en raison des cultures intercalaires sorgho-KAT B1 et Sorgho-KAT X56, respectivement. La teneur en humidit\ue9 plus \ue9lev\ue9e due aux cr\ueates a \ue9t\ue9 attribu\ue9e \ue0 la formation de structures de type bassin, ce qui a augment\ue9 la collecte et l\u2019infiltration de l\u2019eau par rapport \ue0 l\u2019absence de cr\ueates o\uf9 le ruissellement de surface \ue9tait pr\ue9dominant. La teneur en humidit\ue9 la plus \ue9lev\ue9e \ue9tait sur le haricot unique, suivi du sorgho unique, puis de la culture intercalaire sorgho/haricot. La diminution de la teneur en humidit\ue9 dans les cultures intercalaires de sorgho/haricot par rapport \ue0 leurs cultures uniques sp\ue9cifiques a \ue9t\ue9 attribu\ue9e \ue0 une densit\ue9 de culture plus \ue9lev\ue9e, qui a r\ue9duit l\u2019espacement des cultures, d\ue9clenchant une comp\ue9tition pour l\u2019humidit\ue9 disponible du sol. Les rendements les plus \ue9lev\ue9s en grain de sorgho et en \ue9quivalent ont \ue9t\ue9 obtenus dans les parcelles butt\ue9es. La culture intercalaire a entra\ueen\ue9 une diminution du rendement en grains de sorgho, mais a entra\ueen\ue9 une augmentation du rendement \ue9quivalent en sorgho (SEY) et du rapport d\u2019\ue9quivalent en terres (LER). Les r\ue9sultats montrent que le billonnage et la culture intercalaire conviennent \ue0 une plus grande efficacit\ue9 de l\u2019utilisation de l\u2019eau et \ue0 la productivit\ue9 des terres dans les TASA du Kenya

Investigation of 3D non-random porous structures by fused deposition modelling

The development of 3D non-random porous structures for biomedical applications has been of interest for many years. Processing of these 3D non-random porous structures using the fused deposition modelling (FDM) process is presented in this paper. The FDM built structures were evaluated to determine their suitability for use in the area of tissue engineering. The influence of process parameters on the porosity, pore diameter and compressive strength of the porous structures was investigated. The FDM process was found to be able to provide good control and reproducibility of the desired degree of porosity and 3D microstructure. This technology also offers flexibility and ease of varying the microstructure to meet specific structural and functional requirements for tissue engineering