No abstract

Low agricultural output and a decline in plant-available nutrient content in soil pose significant challenges to developing countries. To test the hypothesis that poultry litter and its biochar improve soil quality, nutrient status, and plant growth, a greenhouse pot experiment with sandy-loam soil was conducted. Selected application rates of poultry litter (0, 15, 30, 60, and 120 g/kg) and its biochar pyrolyzed at 350 °C and 600 °C were used. With the addition of organic amendments, Jatropha plant height, leaf number, and stem diameter improved significantly, as did soil fertility indicators (pH, organic matter content, cation exchange capacity, and plant-available nutrients). When compared to the control, increased application rates ranging from 60 g/kg to 120 g/kg significantly improved soil properties and plant growth. PL (Poultry litter)- and BC350 (Biochar produced at 350 °C)-treated soil outperformed other organic amendments in terms of soil quality, nutrient status, and plant growth. Soil pH, CEC, and OM were found to be positively correlated with available plant nutrients, with PL-treated soils having higher levels of plant available nutrients. Because the properties of the feedstocks complement each other, combined organic amendments improved studied parameters, particularly PLBC600 (Poultry litter mixed with biochar produced at 600 °C) compared to BC600 (Biochar produced at 600 °C). Increased application rates of pure and combined feedstock effectively increased soil fertility and Jatropha growth; however, lower temperature biochar is recommended for use as a soil organic amendment.

No abstract

Poultry litter and biochar contribute to improved plant growth due to their high nutrient content. However, to the best of our knowledge, how incorporating poultry litter and its biochar in soil affects photosynthesis-related parameters of Jatropha curcas L. has not been reported. Therefore, a greenhouse pot experiment was conducted using a complete randomised design with three replicates per treatment to determine the effects of poultry litter, biochar pyrolysed at 350 °C and 750 °C at different application rates (0, 0.5, 1, 2, 3 gkg-1) on Jatropha curcas L. photosynthesis parameters.  The control plants recorded the lowest values of photosynthesis-related parameters compared to the treated plants except for water use efficiency. The study observed a significant (P < 0.05) increase in leaf surface area (1807 m2, PL), dark-adapted Fv/Fm ratio, carbon dioxide uptake, and transpiration rate for PL and BC350 with increased application rates, compared to BC750 treatments. BC350 treated plants exhibited higher values (0.79) of Light-adapted Fv’/Fm’. The quantum yield of PSII electron transport displayed an increase with an application rate of 3 gkg-1in PL (0.75) treated soils. Comparing organic amendments used, BC350 exhibited a significantly higher value of carbon dioxide uptake rate (2.67 μmol m-2 s-1) and transpiration rate (2.20 mmol m-2 s-1); however, WUE increased at an application rate of 3 gkg-1 in BC750 (3.8 µmol (CO2) mol-1(H2O)) treated plants. The study results indicate that poultry litter and biochar produced at a lower temperature significantly improved photosynthesis parameters than biochar produced at a higher temperature.