Evaluation of irrigation water quality and its nutrients contribution in Java

Inglés. Irrigation water contributes several kind of nutrients to lowland rice and sometimes creates some problems. Since the first "five years development" research on irrigation water connected with fertilizers requirement and its effect on plant growth and crop yield was still limited. Eighty one water samples from West Java, 88 samples from Central Java and 123 samples from East Java were analyzed for their anion and cation, they were also evaluated for their quality at the laboratory of Center for Soil and Agroclimate Research, Bogor. The results showed that almost all of irrigation water in Java were suitable and did not give any unfavorable effect on the growth and yield of rice plant. Irrigation water in West Java, Central Java, and East Java consecutively could supply 3-25, 3-30, and 7-35 kg N/ha/season; 7-47, 12-35, and 20-74 kg K/ha/season; 25-99, 0-118, and 0-110 kg S/ha/season; 86-226, 84-428, and 176-428 kg Ca/ha/season; and 23-81, 28-86, and 60-145 kg Mg/ha/seasom respectively. The amount of nutrients supply have to be considered in the decision of fertilizer need. Most of irrigation water samples contained 1,000 mg of mud/I but some of them contained 5,000 mg/I. Along with the high content of mud, ion na+, Cl, and SO4 content were also high. Determination of PO4, Fe, Al, and Mn should be considered in irrigation water analysis whether it is necessary to be done

Indonesio. Air pengairan menyumbang beberapa macam unsur hara untuk padi sawah dan ada kalanya menimbulkan masalah. Penelitian kualitas air pengairan dalam kaitannya dengan kebutuhan pupuk dan pengaruhnya terhadap pertumbuhan dan hasil tanaman, sejak Pelita I belum banyak dilakukan. Sejumlah 81 air contoh dari Jawa Barat, 88 contoh dari Jawa Tengah, dan 123 contoh dari Jawa Timur telah dianalisis susunan kation dan anionnya serta dievaluasi kualitasnya di laboratorium Pusat Penelitian Tanah dan Agroklimat. Hasil evaluasi kualitas air menunjukkan hampir semua air pengairan di Jawa cukup baik dan tidak akan berpengaruh buruk pada pertumbuhan dan hasil tanaman. Air pengairan di Jawa Barat, Jawa Tengah, dan Jawa Timur berturut-turut dapat menyumbang: 3-25, 3-30, dan 7-35 kg N/ha/musim; 7-47, 12-35, dan 20-74 kg K/ha musim; 25-99, 0-118, dan 0-110 kg S/ha/musim, 86-226, 84-428, dan 176-428 kg Ca/ha musim serta 23-81, 28-86, dan 60-145 kg Mg/ha/musim. Jumlah sumbangan hara perlu diperhatikan dalam menentukan kebutuhan pupuk. Sebagian besar air pengairan mengandung lumpur 1.000 mg/l, tetapi ada yang mencapai 5.000 mg/l. Tingginya kandungan lumpur disertai tingginya kandungan ion Na dan Cl atau SO4. Penetapan kandungan ion PO4, Fe, Al, dan Mn dalam analisis air pengairan perlu dipertimbangkan apakah layak dilakukan