Effect of preceding fodder crops on the nitrogen requirement of tall wheat

Abstract

S U M M A R YIn a 2-year field study, leguminous fodder crops (cowpea (Vigna unguiculata) and cluster bean (Cyamopsis tetragonoloba)) responded more to P than did nonleguminous fodder crops (maize (Zea mays), sorghum (Sorghum bicolor) and pearl millet (Pennisetum americanum)). The local cultivar of tall wheat, C306, yielded more when sown after fallow or legumes than after nonlegumes. Wheat sown after fallow or legumes produced more ear-bearing tillers and more grains per ear than when sown after nonlegumes. Wheat sown after fallow or legumes responded to N application of up to 20 kg/ha, while when sown after nonlegumes it responded linearly to the highest rate of 60 kg/ha. Thus, preceding fallow, cowpea and cluster bean reduced the N requirement of wheat by 20-40 kg/ha compared with preceding maize, sorghum and pearl millet. Nitrogen increased grain yields only at applications of up to 40 kg/ha because lodging occurred at the higher rates. A cluster bean-wheat cropping sequence proved the most profitable. I N T R O D U C T I O NOnly 30% of India's cultivated area is irrigated, and even in the irrigated areas water is not plentiful, except where canal water is supplemented with tubewell water. The underground water in most parts of the country is unfit for irrigation, except in the vicinity of rivers. In most of the canal-irrigated areas the supply of water is restricted, therefore crops or cultivars with a low water requirement are grown. The wheat C306 is such a cultivar, which reaches maturity with only one-third of the water needed by dwarf high-yielding cultivars. It is grown over large areas under restricted water supply, both in irrigated areas and in rainfed areas of medium to high rainfall. In the latter, C306 is grown in a wheat-fallow rotation to conserve soil moisture. In recent years, increasing demand for more food for human consumption and feed for livestock has necessitated the adoption of multiple cropping. In areas of restricted water supply, quick-growing and short-cycle (60-70 days) fodder crops could be grown during the rainy season; such fodder crops may require less water than the long-cycle (100-110 days) grain crops. The high cost of nitrogenous fertilizers has also led to an interest in effecting N economy by the inclusion of legumes in multiple cropping systems (Narwal & Malik 1987). Little information is available regarding the N requirement of C306 sown after various fodder crops of this region. The present study was, therefore, undertaken to determine the effect of preceding fodder crops on the N requirement of a wheat crop. MATERIALS AND M E T H O D SThe experiments were conducted at the Haryana Agricultural University, Hisar (29° 10' N, 75 ° 40' E, altitude 215 m) during 1983/4 and 1984/5 on an alkaline sandy loam soil (pH 8.2), poor in organic C (0.34%), moderate in available P (9.8 mg/kg) and rich in available K (385 mg/kg). The treatments consisted of (i) five preceding fodder crops (cowpea (Vigna unguiculata (L.) Walp. cv. HFC 42-1), cluster bean (Cyamopsis tetragonoloba (L.) c...

Nitrogen nutrition of wheat following different crops

“…These results agree with those obtained by Graves & McCutchen (1978) and Senigagliesi (1987). Narwal & Malik (1989) obtained similar results when maize was compared with other fodder crops. Nitrate concentration in stem bases measured at 35 DAE (Table 3) was lower for wheat grown after maize than for the other treatments.…”