Nutrient Dynamics and Inventory in Tropical Grassland Ecosystem in Southern India

The present study was to ascertain the distribution of calcium (Ca), magnesium (Mg) and sodium (Na) in the different plant components and in the soil top 30 cm at Kalikesam in Western Ghats region of southern India. Magnesium concentration increased in the order: dead shoots \u3e belowground \u3e litter \u3e aboveground live. Sodium concentration in live shoots was maximum in February (0.51%) and minimum in August (0.05%). Annually 8.94 g/m2 Ca, 2.41g/ m2 Mg and 2.30g/ m2 Na was taken up by plants. The distribution of the three nutrients in plant/soil system indicated that the major portion of the nutrients in the system was retained in the soil, while small fraction of it stayed in plant components. Less than 0.4% of Mg entered the vegetation. Ca and Na entered 16% and 6% respectively

Nutrient Composition and Flux in a Semi-Arid Grazing Land of Southern India

The distribution and cycling of minerals in various compartments of the ecosystem form one of the important aspects of ecosystem study. The uptake of nutrients through the root system and their release via litter and root decomposition depends upon a number of factors including the species, growth and stage of maturity. The semi-arid grazing land ecosystem at Madurai has developed under short evolutionary grazing histories and low moisture regimes, in which grazing pressure has had dramatic effects on the plant community and biomass (Karunaichamy 1992). The biological cycle includes circulation of nutrients between soil and biotic communities by the phenomena of uptake, retention and loss (Duvigneaud and Denacyer 1970). No systematic studies are available on the nutrient cycling of semiarid grazing land of southern India. Therefore, the present study aims to study the distribution of Ca, Mg and Na in vegetation and to estimate the annual nutrient budget in grazed and ungrazed lands dominated by Chrysopogon fulvus (Spreng) Chiov

Nutrient Cycling in a Tropical Grazing Land Ecosystem of Southern India

The nutrient component of any ecosystem operates in a dynamic state through a series of inputs and outputs of the essential elements. Nutrients from plants are continuously transferred to soil via litter formation, which act as a reservoir for the plants in an ecosystem. Most of the studies on nutrient budgets and flux rates have been reported in forest communities and to a lesser degree in grassland. The present study was, therefore, aims to understand the variation of calcium (Ca) and magnesium (Mg) in the vegetation compartments and to quantify annual budget by estimating the annual uptake from soil and its release to soil

Dinamica de la biomasa y produccion primaria neta en pastos tropicales de Ghats occidental en el sur de India

Se estudian la biomasa vegetal, productividad neta primaria y dinámica de transferencia de un pastizal tropical en la región occidental de Ghats, al sur de la India. La mayor cantidad de fitomasa aérea viva se observó en agosto de 1984 (291 g/m2) y la máxima cantidad de biomasa subterránea en marzo de 1984 (74g/m2). La producción primaria neta total anual se estimé en 1946g/m2. La función de transferencia del sistema, mostró que alrededor del 40 p. 100 de la producción total fue encauzada a las partes aéreas y el 60 p. 100 a las partes subterráneas, El output total fue de 4,47 g/m2/día, lo que supone e184 p. 100 del input total. De este modo, el pasto mostró una acumulación neta de materia orgánica excedentaria con que indica su naturaleza serial. Los componentes subterráneos juegan un papel importante en la aceleración del reciclaje a través de la descomposición

Long term yield response of low frequency tapping and yield stimulation in clone RRII 105

An experiment was laid out in the Experimental Farm Unit of Rubber Research Institute of India located at Kottayam, Kerala (9º32'N; 76º36'E) to compare the long term (fifteen years) yield response of clone RRII 105 to low frequency tapping with varying levels of yield stimulation. Reduction in cost of production by adopting low frequency tapping with stimulation (ethephon) is one of the approach to make rubber cost effective. Cumulative dry rubber yield over fifteen years under d3, d4 and d6 frequencies with stimulation is comparable to unstimulated alternate daily tapping (d2). There was no reduction in yield in the renewed bark (BI-1) compared to virgin panel (BO-1) and high yield was obtained in BO-2 panel under d3 and d4 frequencies of tapping. Total tapping days during the study period for d2, d3, d4 and d6 frequencies of tapping days were 2161, 1470, 1105 and 766 days, respectively. Thus, by adopting d3, d4 and d6 frequencies of tapping, requirement of tapper was reduced by 32, 49 and 65 per cent respectively, compared to alternate daily tapping. Benefits of adopting LFT are long term sustainable yield and extended period of tapping on the same panel leading to longer economic life of the trees. Adoption of LFT is also expected to reduce the impact of the scarcity of skilled tappers in rubber plantation sector