Spatial arrangement and Fertility levels in chickpea based inter cropping system under rainfed condition

An investigation entitled “Spatial arrangement and fertility levels in chickpea based intercropping system under rainfed condition” was planned and carried out during rabi-seasons of 2009-10 and 2010-11 at Tirhut College of Agriculture, Dholi Farm of Rajendra Agricultural University, Bihar, Pusa, (Samastipur) to find out compatibility of intercrops and their row ratio with chickpea at appropriate fertilizer level for boosting the productivity of the intercropping system under rainfed condition. The experiment comprised of two intercropping systems, viz. chickpea + mustard and chickpea + linseed, two row arrangement i.e. 6:1 and 6:2 together with sole cropping of each crop and three fertilizer levels of intercrops viz. 50% RDF, 75% RDF and 100% RDF (60:40:40:20 kg, N : P2O5 : K2O : S/ha). The experiment was laid out in randomized block design (factorial) with three replications. Sole crop of chickpea, mustard and linseed were fertilized with recommended dose of fertilizer. The recommended dose of fertilizer (N:P:K:S kg/ha) for the crops were 20:40:20:20 for chickpea and 60:40:40:20 for mustard and linseed. The entire quantity of fertilizers was side dressed at the time of sowing to base as well as component crops in sole as well as in intercropping systems. The crops were sown on December, 2 and November, 24 in first and second year of experimentation, respectively by maintaining rows distance of 30 cm between the rows and 10 cm between plant to plant with the seed rate of 75, 05 and 20 kg/ha to chickpea, mustard and linseed, respectively. The chickpea and linseed were harvested in April while mustard was harvested in March during both the years. Sole chickpea recorded higher number of branches/plant, dry matter accumulation, root length, root dry weight, number and dry weight of nodules/plant and yield indices than both the row ratio of intercropping systems in both the years. Chickpea + linseed (6:1) recorded similar grain yield to sole chickpea. Among the row ratio in intercropping systems, chickpea + linseed (6:1) expressed better growth, better expression of yield attributes and yield, grain : straw ratio and harvest index of chickpea than the chickpea + mustard in 6:1 and 6:2 ratio during both the years. The growth parameters, yield attributes, grain and straw yields, grain: straw ratio and harvest index of chickpea did not vary significantly due to fertilizer levels. Chickpea + mustard irrespective of their row ratios recorded significant reduction in number of larvae/10 plants, number of damaged pods/plant and pod damage percentage over chickpea + linseed and sole chickpea. Higher value of these indices were recorded at 100% RDF than the lower levels of fertilizer but fails to exert significant effect on these indices except to pod damage percentage which were significantly more at 100% RDF than 50% RDF. Nutrient uptake by chickpea did not vary significantly among the intercropping systems. However sole chickpea recorded significantly higher uptake of phosphorus and potassium than chickpea + mustard and chickpea + linseed under both the row ratios while nitrogen uptake in sole chickpea significantly excelled over 6:2 row ratio of chickpea + mustard and chickpea + linseed in second year and at both the row ratios of chickpea + mustard in first year. Nutrients uptake by chickpea did not vary significantly due to different levels of fertilizers in both the years of investigation. Number of branches, dry matter accumulation and yield attributing characters of mustard and linseed were higher in 6:1 row ratio of intercropping than sole crops. However taller plant of both the intercrops was recorded in sole stand. These growth and yield attributing parameters of mustard and linseed were significantly higher at 100% RDF than 50% RDF except plant height of mustard at later crop growth stages, dry matter of mustard at 60 DAS, plant height of linseed at all the growth stages and number of branches of linseed at 30 DAS in both the years. Maximum grain and straw yields of mustard and linseed were recorded in sole stand which were significantly higher over both the row ratios of component crops in intercropping systems. Among the intercropping systems, 6:2 row ratio of chickpea + mustard and chickpea + linseed recorded maximum grain and straw yields which were significantly higher over their 6:1 row ratio in both the years. Grain: straw ratio and harvest index of mustard and linseed in intercropping system as well as sole cropping did not vary significantly. Application of 100% and 75% RDF recorded similar grain and straw yields of mustard and linseed and in turn both were significantly superior to 50% RDF in both the years except straw yield of mustard in first year, where only 100% RDF significantly scored over 50% RDF. Grain: straw ratio and harvest index did not vary significantly among the fertilizer levels. Total uptake of N, P and K by mustard and linseed in both the years were significantly higher in sole stand than their intercropping system. Among the row ratio in intercropping systems, 6:2 row ratio of both the intercropping systems recorded significantly higher uptake of these nutrients by mustard and linseed than 6:1 row ratios in both the years. The nutrients uptake recorded at 100% and 75% RDF were at par and both of them recorded significantly higher uptake over 50% RDF in both the years. Total phosphorus and potassium uptake by the crops in intercropping systems were significantly higher in 6:2 row ratio of chickpea + mustard than both the row ratios of chickpea + linseed and sole chickpea but was at par to 6:1 row ratio of chickpea + mustard. Uptake of these nutrients remained unaffected due to fertility levels. The maximum chickpea equivalent yield (CEY) was recorded in 6:1 row ratio of chickpea + mustard (2233 and 2501 kg/ha) being at par with 6:2 row ratio of same intercropping and significantly higher over both the row ratio of chickpea + linseed and sole chickpea in both the years. Fertility levels had non-significant effect on CEY in both the years. Land equivalent ratio (LER) did not vary significantly among the row ratio in intercropping systems, only 6:1 row ratio of chickpea + mustard (1.15 and 1.16) recorded significantly higher LER over sole chickpea in both the years. LER also did not vary significantly among different fertilizer levels. Gross return did not vary significantly among the intercropping systems however, showed significant variation compared to sole chickpea. Pooled data revealed that chickpea + mustard in 6:1 row ratio recorded significantly higher gross return (Rs. 66325/ha) than sole chickpea (Rs. 56867/ha). Maximum net return on pooled basis was recorded in 6:1 row ratio of chickpea + mustard (Rs. 44828/ha) but was found at par with 6:2 row ratio of chickpea + mustard (Rs. 44758/ha) and in turn both significantly scored over chickpea + linseed at both the row ratios (Rs. 40082 and Rs. 39503/ha) and sole chickpea (Rs. 34716/ha). Higher B:C ratio was accrued under 6:2 row ratio of chickpea + mustard (2.10) however was at par with 6:1 row ratio of chickpea + mustard (2.08) and both treatments proved their superiority over chickpea + linseed at both row ratios (1.88 and 13.85) and sole chickpea (1.57). Gross return, net return and B: C ratio did not vary significantly among the fertilizer levels.