In semi-arid regions, climate change has affected crop growing season length and sowing time, potentially causing low yield of the rainfed staple crop pearl millet (Pennisetum glaucum L.) and food insecurity among smallholder farmers. In this study, we used 1994–2023 rainfall data from Namibia’s semi-arid North-Central Region (NCR), receiving November–April summer rainfall, to analyze rainfall patterns and trends and their implications on the growing season to propose climate adaptation options for the region. The results revealed high annual and monthly rainfall variabilities, with nonsignificant negative trends for November–February rainfalls, implying a shortening growing season. Furthermore, we determined the effects of sowing date on grain yields of the early-maturing Okashana-2 and local landrace Kantana pearl millet varieties and the optimal sowing window for the region, using data from a two-year split-plot field experiment conducted at the University of Namibia—Ogongo Campus, NCR, during the rainy season. Cubic polynomial regression models were applied to grain-yield data sets to predict grain production for any sowing date between January and March. Both varieties produced the highest grain yields under January sowings, with Kantana exhibiting a higher yield potential than Okashana-2. Kantana, sown by 14 January, had a yield advantage of up to 36% over Okashana-2, but its yield gradually reduced with delays in sowing. Okashana-2 exhibited higher yield stability across January sowings, surpassing Kantana’s yields by up to 9.4% following the 14 January sowing. We determined the pearl millet optimal sowing window for the NCR to be from 1–7 and 1–21 January for Kantana and Okashana-2, respectively. These results suggest that co-cultivation of early and late pearl millet varieties and growing early-maturing varieties under delayed seasons could stabilize grain production in northern Namibia and enhance farmers’ climate adaptation. Policymakers for semi-arid agricultural regions could utilize this information to adjust local seed systems and extension strategies.

This study compared the effects of three supplementary diets—egg yolk, Artemia, and commercial pellets with 48% crude protein—on the growth performance and survival rate of redbreast tilapia (Coptodon rendalli) under intensive culture conditions at the Kamutjonga Inland Fisheries Institute in the Kavango East region of Namibia. The study was conducted from December 2023 to January 2024 using a complete randomized design replicated thrice. Results showed that fish fed with commercial pellets exhibited the highest specific growth rate (1.39 ± 0.80%) compared to egg yolk (0.94 ± 0.54%) and Artemia (0.33 ± 0.19%). Commercial pellets also had the best survival rate (76.19 ± 43.099), compared to egg yolk and Artemia (70.47 ± 40.69; 33 ± 19.05), respectively. However, egg yolk had the best feed conversion ratio (0.20 ± 0.05) compared to the commercial pellets (0.22 ± 0.04) and Artemia (0.26 ± 0.07). Critical water quality parameters were maintained within acceptable survival ranges for C. rendalli across all treatments. These findings highlight the importance of dietary protein content in optimizing the growth and survival of C. rendalli under intensive culture conditions and provide insights for effective feeding strategies. However, commercial pellets are expensive and inaccessible to small-scale fish farmers. As an alternative, egg yolk emerged as a viable and affordable feed option, promoting fish growth and supporting the establishment of small-scale farming practices in the region.

Fish Processing and Exports on the Zambezi/Chobe Floodplain, Zambezi Region, Namibia

In semiarid regions, soil salinity, like drought, restricts crop productivity, causing food shortages among most inhabitants—the smallholder subsistence farmers. Seasonal wetlands formed in these regions during the rainy seasons could be utilised for rice (Oryza spp.) cultivation to increase food security, but rice is sensitive to salinity. Field and greenhouse-pot experiments were performed at the University of Namibia-Ogongo Campus, North-Central Namibia, to evaluate rice genotypes’ responses to seasonal wetland salinity. The field experiments assessed 16 rice genotypes for growth during the dry season and grain production during the rainy season, in saline and non-saline (control) seasonal wetlands. The saline-wetland salinity was predominantly NaCl; electrical conductivity levels increased from 2.8 dS m⁻¹ (rainy season) to 34.3 dS m⁻¹ (dry season), resulting in a 0–14% dry-season plant survival rate. The rainy-season wetland salinity decreased paddy yields in all rice genotypes; however, Pokkali produced the highest paddy and relative yields. The pot experiment assessed CG14 (salt-sensitive) and Pokkali (salt-tolerant) genotypes for growth using soils collected bi-monthly from the saline wetland. The rainy-season soil salinity reduced shoot growth in CG14 but did not affect growth in Pokkali, while the dry-season salinity killed both genotypes. The results of this study suggest the possibility of cultivating the salt-tolerant rice genotype, Pokkali, in the saline wetland during the rainy season due to salt dilution; however, the dry-season salinity levels would be detrimental to rice. More salinity-tolerance screening studies are warranted, in order to increase rice production and food security in Namibia and other flood-prone semiarid regions worldwide.