Hydrogel amendment to sandy soil reduces irrigation frequency and improves the biomass of Agrostis stolonifera

Soil water potential indicates the water status of the soil and the need for irrigation. The effect of hydrogel amendment to the upper sand soil layer on water infiltration into the lower un-amended sand layer, irrigation frequency, water use efficiency and biomass production of Agrostis stolonifera was investigated. The upper 25 cm sand layer in three identical buckets was amended at 0.4%, 0.2% and a control (no hydrogel) while the lower 25 cm sand layer separated from the upper layer by a wire mesh in the same buckets was un-amended. Agrostis stolonifera seeds were sown in each bucket and adequately irrigated using a hand sprayer. Potential meter electrodes were inserted at three random positions in each of the buckets and subsequent irrigations were done when a pressure of 600 bars was recorded in any of the three treatments. Data were collected on irrigation frequency, water content in the lower layer, water use efficiency and biomass production of Agrostis stolonifera. The mean water potential in the lower 25 cm layer un-amended sand was significantly more negative in the 0.4% hydrogel than in the control. More water content (10%) was recorded in the lower layer under the control bucket than in either the 0.2% and 0.4% hydrogel amended buckets. The frequency of irrigation was three-fold in the control compared to the 0.4% hydrogel amended sand. The hydrogel amended sand significantly increased the shoot and root biomass of Agrostis stolonifera by 2.2 and 4 times respectively compared to the control. The 0.4% hydrogel amendment in sand increased the water use efficiency of grass eight fold with respect to the control. The hydrogel stimulated development of a dense root network and root aggregation that increased contact of the roots with moisture thus improving water use efficiency of hydrogel amended soil. The results suggest that hydrogels can improve sandy soil properties for plant growth by absorbing and keeping water longer in the soil matrix thus reducing watering frequency.

Cultural knowledge of forests and allied tree system management around Mabira Forest Reserve,Uganda

The cultural universe is sometimes confusing,surprising and murky,so many cultural maps get drawn,discussed and envisioned.A study was undertaken around Mabira Forest Reserve in central Uganda to identify the trees and shrubs culturally managed on-farm,assess the cultural practices of forest and tree system management and determine the relationship between farmer gender and forest and tree system management.We engaged 203 farmers in focus group discussions and semi-structured interviews to collect data.Qualitative data were jointly evaluated with farmers;quantitative data were analyzed in SPSS 20.0.The results showed a high likelihood for involvement of local people in tree or forest management for economic gain,as timber and fast-growing species were highly ranked.Food and medicinal species were also regarded as important,suggesting high prospects of integrating them into the local farming system or protecting them in the forest.Numerous cultural practices(including rituals,trenching,bark slashing,ring barking,spot weeding and use of organic manure and pesticides)of forest and tree system management were acknowledged.However,their knowledge was mixed and unclear about distinct cultural and supportive arrangements for natural forest and tree restoration.While gender was not a significant cultural attribute for knowledge of the forest and allied tree system management,age substantially affected farmer propensity for various timber products.Also farmer’s family size influenced the collection of tree wildings and fodder.We encourage considering gender disparities and livelihood needs including income,during selection of cultural practices for forest and tree restoration.