Produção e valor nutritivo da grama bermuda Florakirk [Cynodon dactylon (L.) pers.] em diferentes idades de crescimento Yield and nutritive value of Florakirk bermudagrass [Cynodon dactylon (L.) pers.] at different plant ages

O experimento foi conduzido em Itapetininga/SP, numa pastagem de Florakirk (Cynodon dactylon) formada há um ano, com o objetivo de avaliar a produção, composição químico-bromatológica e digestibilidade do cultivar em função da sua idade de crescimento. Utilizou-se o delineamento de blocos ao acaso, com 6 tratamentos (idades de crescimento definidas por cortes realizados aos 20, 30, 40, 50, 60 e 70 dias após o corte de uniformização) e 4 repetições. A produção de matéria seca da parte aérea aumentou de forma quadrática (P<0,05), com valor máximo de 215 g m-2, aos 70 dias. A digestibilidade verdadeira in vitro da matéria orgânica decresceu entre 20 e 70 dias (de 711 para 549 g kg-1), enquanto os teores de fibra em detergente neutro e fibra em detergente ácido aumentaram de forma quadrática (P<0,05). Os teores de N, P, K, Mg e Ca decresceram com o aumento da idade, não havendo diferença na concentração de S entre 20 e 60 dias. Foi observada uma maior variação na concentração de macronutrientes que na de micronutrientes (Cu, Fe, Mn e Zn) com o aumento na idade da planta, não havendo influência da idade sobre a concentração de B na planta. No corte aos 40 dias de crescimento, observou-se a melhor combinação entre valor nutritivo e produção de matéria seca da forragem. Observou-se a ocorrência de cigarrinhas e doenças foliares, que pode ter afetado o desenvolvimento da pastagem.<br>This research was conducted in Itapetininga, SP, Brazil, using a one year-old pasture, with the objective of evaluating the effect of plant age on yield, chemical and mineral composition, and digestibility of Florakirk bermudagrass (Cynodon dactylon). The experimental design consisted of randomized complete blocks, with six treatments replicated four times. Treatments consisted of six cutting ages (20-70 days) at ten-day intervals. Dry matter yield increased quadratically (P<0.05), reaching a maximum at 70 days (215 g m-2). In vitro organic matter digestibility decreased (711 g to 549 g kg-1) between 20 to 70 days. Neutral detergent fiber and acid detergent fiber increased quadratically (P<0.05) as age increased. N, P, K, Mg, and Ca concentration decreased with increasing age. There was no difference (P>0.05) in S concentration between 20 and 60 days. A larger variation for macronutrient concentrations was observed than for micronutrient (Cu, Fe, Mn, and Zn) concentrations with increasing plant age. There was no influence of age on B concentration. The best association of nutritive value and yield was observed at 40 days. Occurrence of the spittlebug and foliar diseases was observed, which probably retarded the vegetative and maturity processes

The productivity and response to inorganic fertilizers of species- rich wetland hay meadows on the Somerset Moors: nitrogen response under hay cutting and aftermath grazing

The productivity and response to fertilizer nitrogen (N) was measured in herb-rich wetland hay meadows within a Site of Special Scientific Interest (SSSI) in Somerset, UK. Output from hay cut after 1 July each year and from beef production at aftermath grazing was measured over a total of 4 years. Total utilized metabolizable energy (UME) output averaged from 40.6 GJ ha-1 year-1 without fertilizers to 61.7 GJ ha-1 at 200 kg N ha-1 (N-200), the highest rate used, with about two-thirds of this output from hay. N response was markedly curvilinear above about 50 kg N ha-1, but data from a concurrent experiment suggested that the comparatively low replacement rates of P and K applied were limiting at higher N rates. When hay cutting was delayed until early August in a wet year, yield response to N was lost because fertilized swards had passed a peak in yield several weeks before harvest. Compared with other published data, the results suggest that output and response to N is not constrained by the diversity of the flora or the damp conditions. The data will help to estimate the financial implications for farmers of restricted or zero fertilizer use within SSSIs and the wider Environmentally Sensitive Areas

African heritage in a changing climate

Climate change is a real and present threat to heritage across the world. In Europe and North America, research on the impacts of climate change on heritage, including how to mitigate against more frequent extreme weather events and how to implement efficient sustainable adaptation planning, are now key foci of heritage literature. In contrast, virtually nothing has been written about the impacts of climate change on heritage on the African continent, even though these will be significant in the coming decades. Heritage is essential for livelihoods, but also for the construction and reinforcement of identity and the psychological wellbeing of society. Here, we consider the impacts of climate change on different (connected) forms of heritage in Africa, including archaeological, historical and living heritage. We situate the implications of climate change for African heritage in recent debates around climate justice, sustainability and social wellbeing. We conclude that without significant intervention some of Africa’s most important heritage will be lost as a result of the direct and indirect impacts of climate change over the coming decades. Our intention is to draw attention to the need for research into the impacts of climate change on different forms of heritage in Africa and to highlight the possible deleterious effects these losses will have on society more generally. We view this paper as a first step in developing a research agenda that will have a practical application for the management of heritage in the face of climate change in Africa