Application of P fertiliser is essential to achieve\u00a0optimal oil palm yield production throughout\u00a0Sumatra. Two trials were carried out in Sumatra,\u00a0one in the north on a typical acid volcanic soil\u00a0dominated by rhyolite and the other in the south\u00a0on a representative acid volcanic\/sedimentary\u00a0soil dominated by dacite, to determine the most\u00a0suitable P fertiliser type in these locations. The\u00a0trials compared the effects of triple super phosphate\u00a0(TSP), Egyptian rock phosphate (ERP), Christmas\u00a0Island rock phosphate (CIRP) and China rock\u00a0phosphate (CRP), which have soluble P contents in\u00a0that order, in conjunction with two rates of muriate\u00a0of potash (MOP).<\/p>\n
As expected from its highly soluble P content,\u00a0TSP increased leaf and rachis P more effectively\u00a0than all the other rock phosphates tested in both trials.\u00a0Thus, in the trial in the north, rock phosphate\u00a0is required at a higher P2O5 rate to achieve the same\u00a0yield. A similar optimal yield and rachis P level in\u00a0this trial was obtained at 1.9 kg TSP (0.9 kg P2O5),\u00a04.5 kg CIRP (1.4 kg P2O5) and 3.4 kg CRP (1.0 kg\u00a0P2O5) per palm per year. However, because TSP\u00a0generally costs more than twice the costs of rock\u00a0phosphates, it is usually more economic to use the\u00a0latter.<\/p>\n
In the trial in the south, both CIRP and ERP\u00a0were surprisingly found to be as effective as TSP\u00a0in increasing yield when applied at the same P2O5\u00a0rate, despite having less effect on leaf and rachis P levels. The optimal yields in this trial were obtained\u00a0with 2.7 kg TSP (1.2 kg P2O5), 6 kg CIRP (1.8 kg\u00a0P2O5) and 3.6 kg ERP (1.0 kg P2O5) per palm per\u00a0year. At typical fertiliser prices, ERP was the most\u00a0economic and TSP the least economic. The reason\u00a0for the poorer performance of TSP in this trial is explained\u00a0by its depressive effect on leaf K, due to its\u00a0higher soluble Ca content (although it has a lower\u00a0Comparison of the Effects of Different Types of P\u00a0Fertiliser Applied to Oil Palm in Sumatra\u00a0total Ca content). ERP, in contrast to CIRP, did not\u00a0depress leaf K and increased rachis P more due to its\u00a0higher soluble P content, so was the more effective\u00a0rock phosphate fertiliser.\u00a0<\/p>\n
Although TSP is always more effective in increasing\u00a0tissue P levels of oil palm, it is usually the\u00a0poor choice as a P fertiliser due to its high cost and\u00a0depressive effect on palm K status on soils low in\u00a0reserve K (as in the south of Sumatra but not in\u00a0the north). Any rock phosphate is usually a better\u00a0choice than TSP and in these trials, ERP, which had\u00a0a higher soluble P content, was the most effective\u00a0and economic.<\/p>\n
Aplikasi baja P penting untuk mencapai hasil\u00a0pengeluaran sawit yang optimum di seluruh\u00a0Sumatra. Dua kajian telah dijalankan di Sumatra,\u00a0di bahagian utara di tanah asid gunung berapi biasa\u00a0yang didominasi oleh riyolik (rhyolite) dan di tanah\u00a0asid gunung berapi\/tanah sedimentari di bahagian\u00a0selatan yang didominasi oleh dasik (dacite), untuk\u00a0menentukan jenis baja P yang paling sesuai di\u00a0lokasi tersebut. Kajian ini membandingkan kesan\u00a0penggunaan triple super phosphate (TSP),\u00a0Egyptian rock phosphate (ERP), Christmas\u00a0Island rock phosphate (CIRP) dan China rock\u00a0phosphate (CRP), yang mempunyai kandungan P\u00a0larut mengikut susunan dan kombinasi dengan dua\u00a0kadar peletakan muriate of potash (MOP).<\/em> Dalam kajian di bahagian selatan, kesan CIRP\u00a0dan ERP dalam meningkatkan hasil didapati sama\u00a0seperti TSP apabila diaplikasi dengan kadar P2O5\u00a0yang sama, walaupun menunjukkan tahap kandungan\u00a0P daun dan rakis adalah rendah. Hasil optimum\u00a0dalam kajian ini diperoleh dengan penggunaan\u00a02.7 kg TSP (1.2 kg P2O5), 6 kg CIRP (1.8 kg\u00a0P2O5) dan 3.6 kg ERP (1.0 kg P2O5) per pokok setahun.\u00a0Berdasarkan harga baja secara umum, penggunaan\u00a0ERP adalah paling ekonomik manakala \u00a0penggunaan TSP adalah sebaliknya. Punca kurang\u00a0dengan kesan tekanan pada K daun, akibat kandungan\u00a0Ca larut yang tinggi (walaupun mempunyai\u00a0jumlah kandungan Ca yang rendah). Berbeza dengan\u00a0CIRP, ERP tidak menimbulkan tekanan pada\u00a0K daun tetapi lebih meningkatkan P rakis kerana\u00a0kandungan P larut yang lebih tinggi, maka bertindak\u00a0sebagai baja batuan fosfat yang lebih berkesan.\u00a0<\/em><\/p>\n Walaupun TSP sentiasa didapati lebih berkesan\u00a0dalam meningkatkan tahap P tisu sawit, namum ia\u00a0tidak merupakan pilihan yang tepat sebagai baja P\u00a0berikutan kos yang tinggi dan kesan tekanan pada\u00a0K daun di tanah di mana kandungan K adalah\u00a0rendah (seperti di selatan Sumatra tetapi tidak di\u00a0kawasan utara). Sebarang batuan fosfat biasanya\u00a0lebih berkesan berbanding dengan TSP dan dalam\u00a0kajian ini, ERP yang mengandungi kandungan P\u00a0larut yang paling tinggi, merupakan pilihan yang\u00a0lebih berkesan dan ekonomik.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":" Application of P fertiliser is essential to achieve\u00a0optimal oil palm yield production throughout\u00a0Sumatra. Two trials were carried out in Sumatra,\u00a0one in the north on a typical acid volcanic soil\u00a0dominated by rhyolite and the other in the south\u00a0on a representative acid volcanic\/sedimentary\u00a0soil dominated by dacite, to determine the most\u00a0suitable P fertiliser type in these locations. The\u00a0trials […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[193],"tags":[1265,1266,1267,1268,1269,5],"class_list":["post-2253","post","type-post","status-publish","format-standard","hentry","category-no-65-november-2012","tag-rock-phosphate","tag-superphosphate","tag-p-fertilizer","tag-profitability","tag-antagonistic","tag-oil-palm"],"acf":[],"_links":{"self":[{"href":"http:\/\/opb.mpob.gov.my\/index.php\/wp-json\/wp\/v2\/posts\/2253","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/opb.mpob.gov.my\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/opb.mpob.gov.my\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/opb.mpob.gov.my\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/opb.mpob.gov.my\/index.php\/wp-json\/wp\/v2\/comments?post=2253"}],"version-history":[{"count":0,"href":"http:\/\/opb.mpob.gov.my\/index.php\/wp-json\/wp\/v2\/posts\/2253\/revisions"}],"wp:attachment":[{"href":"http:\/\/opb.mpob.gov.my\/index.php\/wp-json\/wp\/v2\/media?parent=2253"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/opb.mpob.gov.my\/index.php\/wp-json\/wp\/v2\/categories?post=2253"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/opb.mpob.gov.my\/index.php\/wp-json\/wp\/v2\/tags?post=2253"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
Seperti yang dijangka daripada kandungan P larut yang tinggi, TSP lebih berkesan meningkatkan kandungan P di daun dan rakis berbanding dengan rawatan batuan fosfat dalam dua kajian tersebut. Oleh itu, kajian di bahagian utara memerlukan batuan fosfat pada kadar P2O5 yang lebih tinggi untuk mencapai hasil yang sama. Hasil optimum dan tahap P rakis yang sama dalam kajian ini boleh diperoleh melalui penggunaan 1.9 kg TSP (0.9 kg P2O5), 4.5 kg CIRP (1.4 kg P2O5) dan 3.4 kg CRP (1.0 kg P2O5) per pokok setahun. Walau bagaimanapun, memandangkan kos TSP adalah lebih dua kali ganda daripada kos batuan fos fat, maka penggunaan batuan fosfat menjadi lebih ekonomik.<\/em><\/p>\n