Asian Journal of Research in Agriculture and Forestry

Net primary production (NPP) is an important index for understanding carbon cycling in forest ecosystems. In this study, aboveground NPP at Acacia mangium plantation was estimated basing on allometry for aboveground biomass increment (ΔM) and litter trap technique for litterfall (Lf). The experiment was conducted in two plots of 300 m² each (15 × 20 m), established at a 21-month old plantation. Data were collected five times of 3-month intervals in a total duration of 357 days. The results indicated that Lf and ΔM were seasonal-dependent. Litterfall was highest (4.06 g m^-1 day^-1) during Sep-Jan (late rainy season, early winter) and lowest (1.10 g m^-1 day^-1) during Mar-Jun (early rainy season, early summer). While, ΔM was highest (13.51 g m^-1 day^-1) during Jun-Sep (rainy season, summer) and lowest (3.10 g m^-1 day^-1) during Jan-Mar (dry season, winter). Total Lf in a duration of 357 days was 9.69 tons ha^-1 and ΔM was 27.71 tons ha^-1, leading to total aboveground NPP of the present study plantation of 37.40 tons ha^-1. It is concluded that aboveground NPP of acacia plantation was much higher than other forests of different types and ages around the world. Such difference indicates the importance of acacia plantation in soil nutrient cycling through litterfall decomposition and carbon sequestration through aboveground biomass increment.

The experiment was conducted in Federal College of Forestry demonstration farm Jos, Plateau State to determine the growth and yield components groundnut as affected by phosphorous fertilizer application on the Jos plateau. The experimental design used was a randomized complete block design (RCBD) comprising of four treatments (0, 20, 40 and 60 kg P ha^-1) that were replicated four times on groundnut (SAMNUT 25). Data was collected on germination percentage, plant height, leaf count, number of branches, days to 50% flowering, number of pods/plant, 100 seeds weight, total yield and biomass weight which were analysed using analysis of variance (ANOVA) at 5% level of probability with Minitab 23. Where significance was declared, Fisher LSD method was used to separate the means. The result reveals that no significant effect was recorded for germination percentage. Highly significant effect of phosphorous was observed on the growth and yield components of groundnut. The highest (34.63 cm) plant height, leaf (100.78) count, number (27.13) of branches, days (27.75 days) to 50% flowering, number (34.50) of pods/plant, 100 seeds (52.08 g) weight, total (2.26tha^-1) yield and biomass (5.42 tha^-1) weight at the application of 60 kg P ha^-1. Thus, groundnut farmers are encouraged to engage in the application of 60kg P ha^-1 for optimum growth and yield. Further research on other varieties should be conducted to ascertain the best variety and phosphorous rate for optimum groundnut production in the study area.

Forest and non-forest products are becoming scarce in Nigeria due to insatiable want of the resources by the people. The performance of public sector forest plantation development in Nigeria has fallen short of expectation of various stakeholders, hence, the need for investment in Private Forest Plantation Development (PFPD), fostered towards increasing wood supply and reducing the pressure on natural forest. In this study, investment analysis of medium scale PFPD was investigated to show its feasibility.  Measures such as Net Present Value (NPV), Benefit Cost Ratio (BCR), Internal Rate of Return (IRR), Annual Equivalent Value (AEV), Land Expected Value (LEV), Return on Investment (ROI) and Discounted Payback Period (DPBP) were used to analyse the cash flow statement of the investment.

The study showed that medium scale of Tectona grandis, Gmelina arborea, with few Terminalia spp. plantation of 20ha with 18 year rotation had NPV of ₦1,504,841.70, BCR of 1.35, IRR of 24.03%, AEV of ₦316,016.76ha^-1, LEV of ₦2,186,997.89ha^-1, ROI of 35% and DPBP of 17.7years.  The results showed that the investment is feasible based on economic returns indices. It is recommended that PFPD should incorporate multiple land use systems and apply appropriate silvicultural techniques in order to maximize the net return.

In Sri Lanka excessive use of pesticides in paddy and vegetable farming has caused much concern in terms of its impact on the environment and humans. A study was done in Eastern Sri Lanka to find out vegetable farmer’s awareness of hazard levels of pesticides, perception of pesticide impact on the environment and their health, and awareness about different methods of pest control among farmers. A multi-staged random sample of 96 vegetable farmers in five Agrarian Service Center ranges in the Eastern Province of Sri Lanka was studied, during October to November 2017, using a structured questionnaire. Frequencies estimation and Chi Square tests were done to find relationships. The results indicated that the degree of awareness on the hazardous levels of pesticides was minimal, but their perceptions on the impacts of the pesticides on the environment, humans, animals and on food items sold was high among the vegetable farmers. There was a significant spatial variation in knowledge on hazardous level of pesticides used in vegetable production. Significant differences existed between areas studied on the perception of farmers of the impact of pesticides on humans, animals, food and environment. Most of the farmers were aware about crop rotation, chemical control and manual control methods to get rid of pests. Only a low percentage of farmers were aware about biological control, cultural control and seed treatment to curtail pest attack. There were significant spatial differences in farmers’ awareness on available pest control methods. Policy makers and institutions intervening to regulate pesticides usage need to adopt multiple strategies to create awareness on the impact of pesticides on humans and the environment, through designing policies to enhance farm extension services and to encourage adoption of alternative methods of pest control.

This study was carried out to examine deforestation and rural household income with a view to ensuring conservation. A multistage sampling procedure with a 3-stage design was used for this study. Questionnaire was used to elicit information from 120 respondents in Odeda local council area of Ogun State, Nigeria. Data collected were analyzed using descriptive and inferential statistics. The Foster-Greer-Thorbecke indices of poverty metrics was used to determine the poverty line of households. Smith’s saliency was used to determine the livelihood activities in selected communities. The result showed that respondents were gender sensitive, majority (58.3%) were male and (41.7%) female. On age, 41 – 50 (45.8%) years recorded the highest. The mean age was 50 years. Most of the respondents were married (68.6%) while majority, (52.5%) have low literacy level attaining only secondary education. Household size 1 - 5 recorded the highest, (76.7%) of the total population. Mean household size was 5. The study area was dominated by Yoruba (77.5%). Major occupation income recorded a mean of N17, 000 Naira while minor occupation income recorded a mean of N4308.37 Naira. Poverty line of N122, 700 Naira was determined with poverty incidence (P₀) of (21.67%). The poverty gap (P₁), (5.09%) indicating that an average respondent requires N6, 245.43 Naira to reach the poverty line. The poverty severity (P₂) was (0.02) showing that the respondents were not poor because the value is far from 1. Socio economic factors promoting deforestation were identified among the respondents with marital status as the only significant variable (P<0.05) and a negatively coefficient value of -2.281. Conclusively, deforestation was identified with livelihood activities of the people such as hunting, farming and trading of forest products. Therefore, it is recommended that forestry extension programmes should be intensified in rural communities to minimize deforestation activities and promote eco-consciousness among the local people.