Kajian tentang persistensi brachiaria humidicola (Rendle) schweick setelah penggembalaan pada lahan perkebunan kelapa

Abstract

Actually, a combination of pasture and cattle system on coconut plantation is not a new practice. In fact, it has been applied for years in Indonesia but no promising results yet. This practice has always ended up with the so-called pasture run down. Therefore, it is not a sustainable practice.Various pasture and grazing management combined with shade tolerant forage were applied, but the production has not reached the target yet. Previous knowledge on the goal of defoliation or grazing is to trim plant‟s shoot to fulfill cattle‟s need (herbage allowance) without considering pasture health to grow and produce forage. Furthermore, grazing time is determined based on plant‟s age. However, due to climate change phenomenon, the temperature has fluctuated irregularly affecting on plant‟s growth and development. Therefore, using plant‟s age as a threshold could be inaccurate. More accurate method can be used by measuring heat unit accummulation to produce one phyllochron. Therefore, the main goal of this research was to increase the productivity of coconut plantation by combining pasture system with cattle. To analyse the persistency of grass plant B. Humidicola, this research was conducted with three objectives: 1) to find out the number of heat units required to produce one phyllochron of single grass plant B. Humidicola living within certain community, and growth patterns of them; 2) to find out effects of defoliation intensity and interval based on plant‟s age (callender days) and daily temperature accummulation (growing degree days) to the production of dry foliage biomass and nutrient content; 3) to measure coconut plantation productivity that has been combined with pasture and cattle, grazing experiment with different grazing methods and stocking rate was used in this study. This research was conducted from April 2008 to October 2010 in the experimental plantation of Coconut and Other Palmae Research Institute, Manado, North Sulawesi. The objective 1 was done to measure the needs of heat units to produce one phyllochron of Brachiaria humidicola plant growth and developed individually, compared to those in the community. Furthermore, growth pattern of the plant was also studied by measuring number of seedlings, nodes, and the length of stolon during of growth development (weeks). Analyses of t- test and deviation standard were used. With regard to objective 2, was studied the effects of intensity and interval of defoliation based on both the ages (days) of plant and the growing degree days, on the dried weight and nutrient content of foliage biomass. Treatments were arranged based on randomized complete block design. Objective 3 of this research was to understand effects of continuing grazing and rotational grazing at different stocking rates to pasture performance. This was measured with dried foliage biomass, population and the development of new shoot, botanical composition, nutrient content, dominant microorganism living 4 within plant‟s root and an increase of cattle weight. Treatments were arranged according to seperate block pattern based on randomized block design. This research found that heat unit requirement to produce one phyllochron was different among plants. Single grass plant required 68,19 degree days to produce one phyllochron while plant growth within a community required 130,44 degree days. The growth pattern of Brachiaria humidicola showed that when this grass growth individually, grew more aggressive than those in community. It was shown that the number of seedlings, nodes, and the length of stolon developed linierely, compared to the other following a quadratic regression pattern. To ensure the persistency of this grass it should be defoliated regularly. Furthermore, interaction of defoliation intensity and interval of defoliation had a significant effect on the production and nutrient content of B. humidicola. The better interaction was found between the cutting height of 10 cm and the ages of plant of 30 and 45 days, and the accumulation of heat units of 456,54 degree days. Third experiment showed that interaction of rotational grazing system with stocking rate of three cattles produced the best pasture. Meanwhile, the best nutrient quality and the highest increase in cattle weight were found in rotational system. Furthermore, the cattle grazing in B. humidicola pasture underneath coconut plantation increased coconut production and pasture sustaianability .

Integrasi padang penggembalaan dan ternak sapi pada perkebunan kelapa bukanlah merupakan sistem yang baru, melainkan sudah lama diterapkan. Kenyataan di lapang sistem integrasi ini belum ada yang berhasil menguntungkan sesuai harapan, sebaliknya selalu diakhiri dengan apa yang dikenal sebagai gejala kerusakan padang penggembalaan (pasture run down), sehingga tidak berkelanjutan. Berbagai manajemen budidaya padang penggembalaan dan manajemen penggembalaan serta penggunaan jenis hijauan yang toleran terhadap naungan telah diterapkan, tetapi masalah tersebut belum terpecahkan. Pemahaman lama tentang tujuan defoliasi atau pemanenan adalah pengambilan bagian pucuk tanaman untuk memenuhi kebutuhan ternak, namun defoliasi dilakukan tanpa mempertimbangkan kesehatan padang penggembalaan. Hal yang penting diperhatikan dalam kegiatan defoliasi adalah aspek biogeokimia antara tanaman padang penggembalaan, ternak, peran mikroorganisme pada lingkungan rizosfer dan cadangan karbohidrat untuk pertumbuhan kembali. Selama ini waktu penggembalaan ditetapkan berdasarkan umur tanaman (hari). Dengan adanya perubahan iklim sebagai dampak pemanasan global, suhu udara yang berperan dalam pemunculan daun berfluktuasi tidak teratur, maka penggunaan umur tanaman sebagai patokan berpotensi terjadi kesalahan. Penetapan yang lebih akurat adalah dengan mengukur akumulasi satuan bahang yang dibutuhkan untuk menghasilkan satu filokron.