Ecosystem components Abiotic components soil factors root anchorage

Ecosystem components • Abiotic components – soil factors : root anchorage, provide water and nutrients for plants, niche or habitat for plants , microorganism and animals – climate factors • Biotic components – primary producers – consumers – decomposers 1

Ecosystem function • Energy flow : follows thermodynamics law ie. energy can be neither created nor destroyed, only change in form. • Nutrients cycling 2

Producer 2 nd trophic level 1 st consumer Heat 3 rd 2 nd consumer comsumed Biomass produced at 1 st trophic level Heat comsumed The losses of energy as it moves through trophic levels Heat 4 th 3

Succession, Competition and Climax • Succession of pasture or rangeland = series of change and dynamic of the component plant species through the changes in abiotic factors (particularly soil factors( • Competition = process which occures when two or more organisms are making common endeavor to gain one or more requisites in excess of the immediate supply • Climax = final state of succession at which components of the community is stable in function or at a dynamic equilibrium 4

Ecology of the pasture • Components – climatic resources – land resources – plant (forage crops) resources – animal resources – human and social resources • Pasture ecosystem 5

Dynamics of the pasture • Nutrients cycling • Water cycling • Species components • Utilization pressure – animal management – stocking systems – conflict in landuse 6

Availability of nurtrients to plants Rocks& parent materials Minerarisation Mobilization Organic form Unavailable nutrients Immobilization Inorganic form Available nutrients 7

Sources of nutrients in pasture ecosystems • Parent materials • Return of excreta – urines : N & P – dung : K • Fertilizer • Supplement feeds • Atmosphere : N 2 8

Yield and nutrient yields of grass sward with return of excreta Treatment DM N )kg/ha( P K Concentrate +Excreta return 6233 132 22. 2 161 No return 4794 106 19. 4 107 Dung 35. 6 19. 8 19. 4 Urine 69. 7 0. 1 99. 5 9 source: Mott, G. O. 1970. Nutrients recycling in pastures. in D. A. Mays ed. Forage Fertilization.

How the fertilizer will affect on the nutrient pool • Rate of application • Kind of fertilizer • Frequency of application : basal, top dress • Management of the pasture : grazing or cut & carry • Accerelating factors : stocking rate, soil fauna & micro-organism 10

Supplement feeds • Concentrates – protein source : soybean meal, fish meal, rubber seed meal, rice brand – carbohydrate source : cassava, corn, broken rice – vitamin & minerals • Conserved feed : cut grass, agricultural wastes or industrial by-product 11

Atmosphere • NH 4, NO 3, NO 2 , SO 4 and dust in rain • Symbiotic N 2 fixation by Legume & Rhizobium spp. • Non synbiotic N 2 fixation by Clostridiun, Azotobacter, Beijerinckia, Derxia spp. 12

Nitrogen cycle N 2 fixation Rhizobium grazing Plant biomass Denitrification Animal biomass Organic N &Humus N 2 Microbial biomass Heterotrophic microbial assimilation NH 4 Mineraization Plant assimilate NO 3 Nitrification 13

Feed Animal products &excreta loss Nitrogen cycle in the components of grassland Plant biomass Animal biomass Organic soil pool Fertilizer Plant products Microbial biomass Inorganic soil pool Leaching &gas loss 14

Animal Products Fertilizer input Animal growth Soil nutrients Animal excreta Fertilizer economy in managed pasture 15

Water cycle Precipitation Transpiration Evaopration Foliar absorption Infiltration Leaching / run off Soil water 16

Succession in pasture (dynamic of botanical composition( • BC vs grazing – selective grazing – palatability – resistance to grazing pressure • BC vs fertilizer input – fertilizer requirement (P, N availability for grasses and/or legumes( • BC vs climatic conditions – drought and floods conditions 17

Grassland types • Temperate zone – – Humid temperate pastures Semi arid temperate pastures Mediterranean pasture (winter rainfall( Sub-tropical pastures • Tropical zone – – Humid tropical Savannah Semi arid tropical pastoral Arid tropical pastoral 20

������� • �������� Natural grassland, Rangeland, Savannah grassland • ����� ��� Man made pasture, – ����� Imperata cylidrica – ������ Arundinaria pusilla Managed pasture or grassland e. g. . – ������ Themeda triandra Brachiaria mutica, – �������� Heteropogon Brachiaria ruziziensis, contortus Panicum maximum, – ����������� Chrysopogon orientalis Paspulum plicatulum, Pennisetum purpureum, – ������ Ischaemum aristatum 21

������� ������ • ���������� Grazing reserved, Communial grassland • �������������������� Shifting or swiden cultivation • ������������� Along roadside and lakeside • ������������ Reserved 22 forest or National park

Grassland management concepts • Goals – ecological stability – sustainable yield • Management – – carrying capacity ; utilisation / supply stocking rate and grazing pressure nutrients and water cycling trophic level and food chain • Other purposes of landuse – resources allocation – man and community 24

Common area to be used by anyone who wishes Lot of grass and timber to be used , I just increse my cows Tragedy of common properties 25

Bibliography Holecheck, J. L. , Pieper, R. D. and Herbel, C. H. 1989. Range Management ; Principles and Pracitces. Prentice Hall. Englewood Cliffs : 501 pp. (SF 85 H 64 1989( Jones, M. B. and Lazenby, A. 1988. The Grass Crop ; The Physiological Basis of Production. Chapman and Hall. London : 369 pp. (SB 197 G 77 1988( Mack, S. 1990. Strategies for Sustainable Animal Agriculture in Developing Countries. FAO, Rome : 271 pp. (SF 75. 2 S 77 1990( Morley, F. H. W. 1981. Grazing Animals ; World Animal Science, B 1. Elsevier Scientific Publishers Co. , Amsterdam: 411 pp. (SF 85 G 72 1981( Roux, E. 1969. Grass ; A Story of Frankenwald. Oxford University Press. London : 212 pp. (QH 541. 5 P 7 R 68 1969( Snaydon, R. W. 1987. Managed Grasslands Analytical Studies ; Ecosystems of the World 17 B. Elsevier Scientific Publishers B. V. , Amsterdam: 285 pp. (SB 199 M 35 1987( UNESCO. 1977. Tropical grazing land ecosystems. UNESCO/UNEP/FAO. 26 Mayenne. 655 pp. (QH 541. 5 U 57 1977(