Effects of Different Green Manures and Fodder Crops on Crop Yields and Phosphorus Needs of Potato–Wheat Systems in the North-Western Plains of India

Abstract

SUMMARYThe tuber yield of potatoes in a field experiment conducted at Jalandhar between 1981 and 1984 was greater following green manuring with either Crotalaria juncea or Sesbania aculeata than after fodder crops of Zea mays or Pennisetum typhoides. The residual effect of phosphorus applied to potato on subsequent wheat crops varied with the previous green manuring and fodder cropping treatments but was always sufficient for the wheat when applied at an economic rate; the lack of an application of phosphorus fertilizer to the wheat did not result in a decline in the availability of soil phosphorus. The use of C. juncea as a green manure increased the availability of phosphorus but decreased that of potassium. Pennisetum typhoides also depleted soil potassium reserves. Sesbania aculeata green manure improved the organic carbon status of soil whereas P. typhoides depleted it.