Pengaruh Pupuk Neutralizer, Kaptan, dan Urea terhadap Caisin Varietas Tosakan pada Podsolik Jasinga

Abstract

Podsolik is one of the acid soil which is poor in nutrient and also contains relatively high exchangeable Aluminium (Al). The level of the exchangeable Al causes low crops production. This condition could be improved by fertilization and manipulating soil reaction. Fertilizers are used to supply nutrients so that it can improve crops growth, increase production, and improve crops quality. The Improvement of soil reaction can be achieved by liming or adding the other materials which have characteristic of lime or increasing soil pH. Liming can be done by agriculture lime or soil ameliorant substance which is expected can be function as lime material. One of the soil ameliorant is “Neutralizer”. Podsolik was used as soil and Caisin as test plant. Treatments which used were Neutralizer, Agriculture Lime, dan Urea. The rates of Neutralizer were N0 (0 ml/polybag), N1 (0,1 ml/polybag), and N2 (0,2 ml/polybag). While rates of agriculture lime were K0 (0 g/polybag), K1 (16,75 g/polybag), and K2 (33,50 g/polybag). For N source, Urea was used and the rates were U1 (4 g/polybag), U2 (8 g/polybag) and U3 (12 g/polybag). The treatments were set up in Completely Randomize Design (CRD) with 3 times replications. The results of the study showed that Neutralizer treatment did not significantly affect on the weight of fresh caisin leaf whereas Agriculture Lime treatment from K0 up to K2 dosage significantly increased the weight of fresh caisin leafs. The Combination of lime with urea and “neutralizer” with urea did not significantly affect on the weight of fresh caisin leaf. Urea treatment significantly increased N level on K0, K1 and K2 but agriculture lime treatment tended to decrease N level of Caisin. By increasing the rates of lime from K0 to K2, the P level of Caisin significantly increased, on the contrary the U1 to U3 treatments significantly decreased P level although between U1 to U2 were not significantly different. Agriculture lime treatment significantly increased K level of Caisin, but Urea treatment tended to reduce K level of Caisin. Urea treatment tended to increase Ca level of Caisin. By increasing the rates of lime from K0 to K2, the pH of soil significantly increased and significantly decreased the exchangeable Al whereas the U1 to U3 treatment only significantly increased the pH of soil. In general, the addition of Neutralizer did not significantly affect on the increase of fresh weight and the decrease of soil exchangeable compare to agriculture lime.

Podsolik merupakan salah satu tanah masam yang miskin unsur hara dan mempunyai Alumunium yang dapat dipertukarkan yang relatif tinggi. Tingginya Al yang dapat dipertukarkan menyebabkan rendahnya produksi tanaman. Kondisi ini dapat diperbaiki dengan pemupukan dan memperbaiki reaksi tanah. Pemupukan berfungsi menyediakan hara sehingga memperbaiki pertumbuhan tanaman, meningkatkan produksi, serta memperbaiki kualitas tanaman. Perbaikan reaksi tanah dapat dilakukan dengan pengapuran atau penambahan bahan lain yang bersifat mengapur atau menaikkan pH tanah. Pengapuran dapat dilakukan dengan Kapur Pertanian atau bahan pembenah tanah yang diharapkan berfungsi sebagai bahan pengapur. Salah satu bahan pembenah tanah tersebut adalah “Neutralizer”. Penelitian ini menggunakan tanah Podsolik Jasinga sebagai media tanam dan Caisin sebagai tanaman uji. Perlakuan yang digunakan adalah Neutralizer, Kaptan, dan Urea. Dosis Neutralizer yang diberikan yaitu : N0 (0 ml/polybag), N1 (0.1 ml/polybag), dan N2 (0.2 ml/polybag). Sedangkan dosis Kaptan yang diberikan yaitu : K0 (0 g/polybag), K1 (16.75 g/polybag), dan K2 (33.50 g/polybag). Untuk menambahkan sumber N diberikan Urea dengan dosis U1 (4 g/polybag), U2 (8 g/polybag), dan U3 (12 g/polybag). Perlakuan disusun dalam Rancangan Acak Lengkap dengan 3 ulangan. Hasil penelitian menunjukkan bahwa perlakuan Neutralizer tidak berpengaruh nyata pada bobot segar daun caisin sedangkan perlakuan Kaptan dari dosis K0 hingga dosis K2 nyata meningkatkan bobot segar daun caisin. Kombinasi antara kapur dan urea dan “neutralizer “ dan urea tidak berpengaruh nyata terhadap bobot segar Caisin. Perlakuan urea nyata meningkatkan kadar N baik pada K0, K1 dan K2 tetapi perlakuan Kaptan cenderung menurunkan kadar N Caisin. Peningkatan dosis kapur dari K0 ke K2 nyata meningkatkan kadar P Caisin sebaliknya perlakuan U1 hingga U3 nyata menurun kadar P meskipun pada U1 ke U2 tidak berbeda nyata. Perlakuan Kaptan nyata meningkatkan kadar K Caisin, tetapi perlakuan Urea cenderung menurunkan kadar K Caisin. Perlakuan Urea cenderung meningkatkan kadar Ca Caisin meskipun tidak nyata. Peningkatan dosis kapur dari K0 ke K2 nyata meningkatkan pH tanah dan nyata menurunkan Al dapat ditukar sedangkan perlakuan U1 hingga U3 hanya nyata meningkatkan pH tanah. Secara umum, pemberian Neutralizer tidak berpengaruh nyata pada peningkatan bobot segar dan penurunan Aldd tanah bila dibandingkan dengan pemberian Kaptan.