Browsing by Author "Chiduza, Cornelius"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Nitrogen Use Efficiency of Quality Protein Maize (Zea mays L.) Genotypes
    (MDPI, 2022-05-05) Adeoluwa, Olusola Oluyinka ; Mutengwa, Charles Shelton ; Chiduza, Cornelius ; Tandzi, Ngoune Liliane
    Use of more nutrient-use efficient Quality Protein Maize (QPM) varieties will likely playa pivotal role in maintaining or increasing crop yields and nutritional values in fields where soils are degraded. This study aimed to: (i) assess the nitrogen use efficiency (NUE) of different QPM inbred lines at various levels of nitrogen (N) fertilizer application; (ii) determine the relationships among NUE indices and yield; and (iii) determine the appropriate rate of fertilizer application for QPM genotypes under conditions of this study. Thirty-two QPM inbred lines were evaluated at 0, 30, 60, 90 and 120 kg N ha−1 N fertilizer application in a split-plot randomized complete block design with two replicates at the University of Fort Hare Crop Research farm, South Africa. Results revealed highly significant differences (p ≤ 0.001) for total nitrogen in biomass (Bio Total N), total nitrogen in grain (G Total N), grain yield, NUE and almost all the indices estimated across N levels. The top three genotypes which showed high-yielding potential at 30 kg N ha−1 include L2 (6.24 t/ha), L3 (6.47 t/ha) and L4 (6.34 t/ha), and were considered the most N-efficient genotypes under low N soils. The highest grain yields (6.74 t/ha) and highest NUtE (Nitrogen Utilization Efficiency) (1.93 kg grain/total N) were obtained at 90 kg N ha−1 . Highly significant and positive correlation coefficients were found between NUE and yield (+0.9), NUE and NUtE (+0.9), NUE and HI (Harvest Index) (+0.5), NUtE and yield (+0.99), HI and yield (+0.5) and NUtE and HI (+0.5). Highest nitrogen uptake efficiency (NUpE) was obtained from the lowest fertilizer rate, which was 30 kg N ha−1
  • Thumbnail Image
    Item
    Soil C sequestration and CO2 fluxes under maize-based Conservation Agriculture systems in the Eastern Cape, South Africa
    (Taylor and Francis, 2021-05-15) Muzangwa, Lindah ; Mnkeni, Pearson Nyari Stephano ; Chiduza, Cornelius
    Traditional farming methods deplete soil carbon and contribute to carbon dioxide (CO2) emissions. We investigated the effects of Conservation Agriculture principles on C sequestration and CO2 flux from two agroecological regions in the Eastern Cape province, South Africa, over five cropping seasons in the period 2012–2015. The field trials were laid in a split–split plot design. The main treatments were the tillage system, as conventional tillage or no-till. The sub-treatments were the crop rotation pattern: maize–fallow–maize (MFM); maize–fallow–soybean (MFS); maize– wheat–maize (MWM); or maize–wheat–soybean (MWS). Residue management after each crop in rotation was residue removal (R–) or residue retention (R+). The biomass and C-inputs by the crop rotations were both in the order: MWM > MWS > MFM > MFS. R+ resulted in greater levels of particulate organic matter (POM) than R–. The former was the only factor to significantly (p < 0.05) increase soil organic carbon (SOC) in the 0–5 cm depth layer at both sites after two years. CO2 flux under conventional tillage was 20% higher than with no-till. The CO2 fluxes were significantly influenced by air temperature (p < 0.001, r2 = 0.41) and soil bulk density (p < 0.001, r2 = 0.16). The results suggest that MWM or MWS crop rotation in conjunction with R+ under no-till offer the greatest potential for biomass and C-inputs, and consequently C sequestration, in sub-humid and semi-arid agroecological regions of South Africa.