T.J.K. Radovich

Implications of Conservation Agriculture for Men's and Women's Workloads Among Marginalized Farmers in the Central Middle Hills of Nepal

Abstract Measures of gender-based labor distribution can contribute to understanding the feasibility of agricultural development in mountainous subsistence farming communities. Conservation agriculture (CA) can provide sustained crop yield and improved soil and water conservation in mountain areas prone to degradation and where few inputs are available. This study sought to measure the gendered labor impacts of CA practices and to assess their feasibility in remote farming communities. We surveyed farmers in 3 tribal villages in the Middle Hills of Nepal, where communities consist of smallholder (<2 ha) farmers cultivating highly sloping, marginal lands. Face-to-face interviews and time allocation surveys were used to quantify distribution of labor and to identify engagement in agricultural decision-making in 87% of the households. On-farm plots were used to measure differences between the gender-based labor demands of conventional and CA practices. Results show that women bear a disproportionate burden (53–55%) of on-farm labor. Field trials showed that women would predominantly manage increases in labor demands from CA, particularly where more labor for plowing, sowing, and harvesting is required, yet 51.3% indicated that they have limited control over adoption of new practices. In situations where women are already overburdened, technologies that require additional labor may prove unsustainable. It is crucial to adapt technologies to provide gender-sensitive solutions and meet the needs of the local community. Identifying the gendered constraints of CA is vital to improving understanding of agricultural livelihoods.

Use of Organic Fertilizers to Enhance Soil Fertility, Plant Growth, and Yield in a Tropical Environment

Soils rarely have sufficient nutrient for crops to reach their potential yield. Applying organic fertilizers without prior knowledge of their properties may cause yield decline under low application or pollute the environment with excessive application. Under‐ standing the nutrient variability and release pattern of organic fertilizers is crucial to supply plants with sufficient nutrients to achieve optimum productivity, while also rebuilding soil fertility and ensuring protection of environmental and natural resour‐ ces. This chapter presents the authors’ experiences with different organic amend‐ ments under Hawaiis tropical conditions, rather than an intensive literature review. For meat and bone meal by‐products (tankage), batch‐to‐batch variability, nutrient content/ release pattern and quality, and plant growth response to the liquid fertilizer pro‐ duced from tankage were evaluated. For animal livestock, dairy manure (DM) and chicken manure (CM) quality, changes in soil properties, and crop biomass produc‐ tion and root distributions were evaluated. For seaweed, an established bio‐security protocol, nutrient, especially potassium (K) variability, and plant growth and yield response were evaluated in different tropical soils.

A Correlation of Rapid Cardy Meter Sap Test and ICP Spectrometry of Dry Tissue for Measuring Potassium (K+) Concentrations in Pak Choi (Brassica Rapa Chinensis Group)

ABSTRACT Nutritional status of vegetable crops is often monitored by analysis of dried plant tissues, which is costly and often time consuming. Two greenhouse trials were conducted, at the University of Hawaii at Manoa, Magoon facilities, to evaluate the portable cardy ion meter (CIM) in determining potassium (K+) status in fresh petiole sap of pak choi as compared with standard laboratory methods. In the first greenhouse trial, three algae species (Gracilaria salicornia, Kappaphycus alvarezii, and Eucheuma denticulatum) were used to apply five rates of K+ (0, 84, 168,252, and 336 kg.ha−1). The pak choi was directly seeded into 4 L pots and was grown in peat moss. In the second greenhouse trial, K+ was provided through Eucheuma denticulatum and potassium nitrate (KNO3) at five rates (0,112, 168, 224, 280, and 336 kg.ha−1) in peat moss and soil media. At harvest, K+ concentrations in fresh petiole sap were analyzed immediately with CIM and the dried samples were analyzed by inductively coupled plasma spectroscopy (ICP) measurement. The results showed increase in leaf K+ content at higher rates and the maximum concentration of leaf K+ at 4500–5300 mg/L for sap and 8–9% for tissue was obtained when K+ was provided between 224 and 284 kg.ha−1. There was a close correlation between the CIM readings and the ICP method (r = 0.8048 and 0.8314) from the first and second GH results, respectively. The results suggest that the CIM could be used for the rapid monitoring of the relative K+ status of plants. The data further suggested 4500–5000 mg K/L for fresh petiole sap and 7.5% K+ in tissue as critical levels for K+ concentration in pak choi.

Effect of Intercropping Three Legume Species on Growth and Yield of Sweet Corn (Zea mays) in Hawaii

In Hawaii, there are many small farm holders. Intercropping may increase diversity of farm products, reduce input costs, and increase farm profitability. Two field experiments were conducted in Hawaii to study the effect of three legume species intercropped with sweet corn (Zea mays L.) on the growth, relative chlorophyll content, biomass, and yield of sweet corn. The treatments included corn + soybean (CS), corn + bush bean (CB), corn + cowpea (CC), and corn alone (CO; control). In the first growing season, 30 days after planting, relative chlorophyll content of corn leaves was significantly higher in CC treatment with 53%, 56%, and 68% compared with CB, CS, and CO, respectively. While, in the second growing season, 30 days after planting, relative chlorophyll content of corn leaves was significantly higher in CC treatment with and 31%, 33%, and 66% compared with CB, CS, and CO, respectively. Corn plants in the CC treatment were significantly taller and had greater leaf area than those in other treatments. Fresh and dry weights of corn biomass, corn + legume biomass (with and without pods), and fresh weight of corn ears were all significantly higher for the CC treatment as compared with the other treatments. Mean fresh weight of corn ears under CC treatment increased by 9.9%, 35.1%, and 53.5% compared with CB, CS, and CO, respectively. The results suggested that lower competition and/or the contribution of fixed N in the CC treatment contributed to the better growth of corn.