Herbage Productivity and Botanical Composition of Hill Pasture as a Function of Clipping and Site Features
Complex topography and varied soil of hill-land pastures create microsite conditions that support an array of floristic associations and herbage production patterns. This complicates management for forage and livestock production because the seasonal distribution and quantity of forage vary. Our objective was to determine herbage production and floristic composition of a hill pasture as a function of site characteristics and canopy management. An existing 3-ha hill pasture watershed was oversown with white clover (Trifolium repens L.) and orchard-grass (Dactylis glomerata L.) and fertilized with reactive phosphate (PO 4 ) rock (PR). Replicated plots on each of four sites were clipped once (stockpiled), twice (hay harvest), or three times (long rotation) annually. Site had a significant impact on cumulative herbage production, whereas the influence of clipping was mixed. The least (1.9 Mg ha -1 ) amount of herbage production in a given season occurred on a northeast (NE)-facing site and the greatest (4.6 Mg ha -1 ) in a natural drainage area (ND) traversing the pasture. Herbage production increased by about 80% with overseeding and PR, but the relative ranking of production among sites stayed the same. Botanical composition was also strongly influenced by site, with velvetgrass (Holcus lanatus L.) predominating in ND and red fescue (Festuca rubra L.) occurring primarily on the NE site. The stockpiled treatments became dominated by grasses and weeds 4 yr after treatments were imposed, regardless of site, and were similar to the least productive site (NE-facing) in the pasture. Our results suggest that application of amendments to the more productive portions of a site are likely to have greater return.
Effects of aspect and topography on pasture production in hill country
Abstract Pasture measurements were obtained from a northerly and a southerly aspect containing several soil strata which were defined by their soil profile characteristics and topography. Each aspect was continuously grazed by sheep at various stocking rates to maintain similar amounts of herbage mass. Over 4 years, the mean annual herbage accumulation and the green content of this herbage were greater on the southerly than the northerly aspect. Within an aspect, strata differed in net herbage accumulation, in the quantity and digestibility of herbage mass, and in botanical composition. Differences were larger on the northerly aspect where moisture-retentive strata were most productive. Variation in herbage accumulation among strata on each aspect was greater within an aspect, than the mean difference between aspects. The herbage mass on the southerly aspect was more digestible than that on the northerly aspect over late summer and autumn although on each aspect digestibility declined over the season.
Students as promoters of rural extension in aquaculture in the Marajó archipelago, Pará, Brazil
Aquaculture is the creation of aquatic organisms. An expanding activity, being of great importance its approach in rural extension. Thus, the objective of this study was to analyze the contribution of extension activities in aquaculture in the professional training of students in Marajó, Amazon, Brazil. The project “Technology transfer through training and technical assistance for tambaqui breeders, Colossoma macropomum, in the archipelago of Marajó/PA” was developed by 10 technician and under graduate students from rural education course and the technical course in aquaculture from the Federal Institute of Education, Science and Technology of Pará (IFPA) Campus Breves, in the city of Curralinho. They participated in the stages of data collection in aquaculture enterprises, training for producers and monitoring of aquaculture production, acting as researchers, instructors and extension workers, respectively. The duration of the project was from August 2019 to March 2020. At the end of the project, a questionnaire was applied to the students involved. The results showed that the aquaculture extension activities developed were relevant and significant, for the construction of knowledge in a mutual way between those involved (students and aquaculture producers). The acquired experiences will substantiate and subsidize the professional practice of these students in a concrete and effective way. In conclusion, the extension project represents an excellent tool in the teaching-learning process for students.