Production Potential and Economic Feasibility of Planting Pattern and Nutrient Management in Pigeonpea (Cajanus cajan) Based Intercropping System under Rainfed Condition

Background: Pigeonpea grown as sole crop is not economically viable because of its slow initial growth rate, low productivity and longer duration. The initial slow growth rate, widely spaced, deep root system and longer duration of pigeonpea offers a good scope for intercropping with fast growing and early maturing compatible crops. Proper row arrangement of main as well as intercrops in appropriate proportion is the promising way to exploit the natural resources such as space, nutrient, sunlight, soil moisture to greater extent and boost up the system productivity.
Methods: The study was carried out for four consecutive years during kharif 2013-14 to 2016-17 at Tirhut College of Agriculture, Dholi, RPCAU, Pusa, Bihar. The treatment comprised 3 intercropping systems with two method of planting viz, pigeonpea (60 cm)+ urdbean (1:1), pigeonpea (60 cm) + sesame (1:1), pigeonpea (60 cm) + sorghum (1:1), pigeonpea paired (45 cm) + urdbean (2:2), pigeonpea paired (45 cm) + sesame (2:2), pigeonpea paired (45 cm) + sorghum (2:2) and 3 fertilizer levels of intercrop viz, 75% recommended dose of fertilizer (RDF), 100% RDF and 125% RDF along with sole crop of pigeonpea, urdbean, sesame and sorghum. 
Result: Intercropping of urd bean [Vignamungo (L.) Hepper], sesame (sesamumindicum (L.) and sorghum (sorghum bicolor (L.) Moench] paired row planting of pigeonpea (45 cm) in 2:2 row ratio recorded significantly higher pigeonpea – equivalent yield, LER, water-use efficiency, production efficiency and net return than their intercropping with pigeonpea in normal planting pattern (60 cm) in 1:1 row ratio and sole pigeonpea. However, only pigeonpea + urdbean and pigeonpea + sesame in paired row planting recorded significantly higher B:C ratio than sole pigeonpea. Pigeonpea + urdbean in paired row planting recorded significantly higher pigeonpea equivalent yield (3.57 t/ha), LER (1.81), water-use efficiency (4.96 kg ha/mm), production efficiency (12.01 kg/ha/day), NPK-uptake by pigeonpea, net return (148.63 x 103 ¹ /ha) and B:C ratio (4.84) than their intercropping in normal planting pattern, pigeonpea + sesame and pigeonpea + sorghum in both planting pattern. Pigeonpea + urdbean and pigeonpea + sesame in paired row recorded significantly higher number and dry weight of nodules/plant than sole pigeonpea. Pigeonpea equivalent yield in pigeonpea + urdbean intercropping system did not increased significantly with increasing levels of fertilizer. However, it increased significantly upto RDF and 125% RDF of sesame and sorghum in pigeonpea + sesame and pigeonpea + sorghum intercropping systems respectively in both the planting pattern. Pigeonpea + urdbean in both the planting pattern reduced bulk density of the soil and increased organic carbon, available N,P,K content of the soil than other intercropping systems and initial soil value but magnitude of improvement in physico-chemical properties of soil was higher in paired row planting.