PENGARUH SAAT TANAM JAGUNG DAN KEDELAI DALAM SISTEM TANAM GANDA TERHADAP PERTUMBUHAN DAN HASIL
EFFECT OF DIFFERENT CORN AND SOYBEAN PLANTING TIME WITHIN MULTIPLE CROPPING SYSTEM TO THEIR GROWTH AND YIELD
Darnawi1, Tohari2, dan Siti Fatimah3
ABSTRACK
The experiment was conduted at Agriculture Training, Reseach, and Development Station of Gadjah Mada University from Frebruary to August 1999. It is aimed to determine the appropriate planting time for maximum growth, yield, Land Equivalence Ratio (LER) value, and Area Time Equivalence Ratio (ATER) value.
Treatments, consisted of seven soybean-corn mutual cultures and two monocultures were arranged in Randomized Complete Block Design with three replications. The soybean and corn cropping-pattern were arranged in additive series. Treatments are concurrent planting time of soybean and corn, delayed planting time of corn 20, 40, 60 days afer soybean, delayed planting time of soybean 2,40, 60 days after corn, corn monoculture, and soybean monoculture. Data were analyzed using analysis of variance and treatment means were compared using Duncan’s new multiple range test.
The results showed that planting time significantly affected growth, yield components, yield, and land productivity. Delayed planting of corn after soybean affected yield of both crop. The concurrent planting decreased soybean yield, but not corn yield. Planting corn 40 days after soybean did not affect soybean yield but decreased corn yield, and delaying corn planting 60 days after soybean might increase soybean yield but did not affect corn yield. Planting soybean after corn did not affect corn yield but decreased soybean yield, except at 60 days after corn. Two highest LER’s (2.21 and 2.143) were achieved at 60 days of corn after soybean planting and 60 days soybean after corn planting. The highest ATER value (1.83) was achieved as corn and soybean planted concurrently.
Keywords : maize, soybean, different planting time, multiple cropping system
INTISARI
PERCOBAAN INI DILAKSANAKAN DI kp4 Kalitirto UGM dari Februari hingga Agustus 1999 untuk menentukan saat tanam yang dapat memberikan pertumbuhan, hasil, Nisbah Kesetaraan Lahan (LER) dan Nisbah Kesetaraan Waktu Lahan (ATER) yang maksimum.
Tujuh perlakuan tumpangsari dan monokultur disusun dalam rancangan acak kelompok lengkap dengan 3 ulangan. Perlakuan-perlakuan meliputi penanaman kedelai dan jagung bersama-sama, penanaman jagung 20, 40, dan 60 hari setelah kedelai, penanaman kedelai 20, 40, dan 60 hari setelah jagung, monokultur jagung dan monokultur kedelai. Data dianalisis secara statistic menggunakan analisis varian dan uji jarak berganda Duncan.
Hasil menunjukkan bahwa saat tanam nyata mempengaruhi pertumbuhan, komponen hasil, hasil dan produktivitas lahan. Penundaan penanaman jagung setelah kedelai mempengaruhi hasil keduanya. Penanaman bersamaan antara kedelai dan jagung menurunkan hasil kedelai tetapi jagung tidak, sementara penundaan jagung 60 hari setelah kedelai dapat menaikkan hasil kedelai tanpa mempengaruhi hasil jagung . Penanaman kedelai setelah jagung tidak mempengaruhi hasil jagung, tetapi hasil kedelai, kecuali penundaan 60 hari setelah jagung. Dua nilai LER tertinggi (2.21 dan 2.143) dicapai disaat penundaan tanaman jagung 60 hari setelah jagung. Nilai ATER tertinggi (1.83) dicapai bila jagung dan kedelai ditanam bersama-sama.
Kata kunci : jagung, kedelai, saat tanam yang berbeda, system tumpangsari.