The present research studies were consisted of two sets of experiments and were conducted during 1999-2000 and 2000-2001 at the Agronomic Research Area, University of Agriculture, Faisalabad (Pakistan). The first set of experiments consisted of inoculated and un-inoculated seed treatments with four levels of phosphorus, i.e., 0, 60, 90 and 120 kg ha-1.
The second experiment included different chickpea based intercropping systems. i.e., chickpea alone, chickpea + one row of wheat, chickpea + two rows of wheat, chickpea + one row of lentil, chickpea + two rows of lentil, chickpea + one row of canola, chickpea + two rows of canola, chickpea + one row of linseed, and chickpea + two rows of linseed. All intercrops were also sown as a sale crop.
The first experiment was laid out in a randomized complete block design with factorial arrangement while a randomized complete block design was used for the second experiment. The net plot size for the first experiment was 1.6 x 5 m while in the second experiment the net plot size was 2.4 x 5 m, chickpea cultivar "Bittal-98 was used as a test crop. The cultivars selected for intercrops were, Inqlab-91 (Wheat), Masoor-85 (lentil), Hiola-401 (Canola) and Chandni (linseed). Seed was drilled in 40-cm spaced rows and Plant-to-Plant distance of 15 cm was maintained by thinning ten days after germination in both experiments. In the second experiment, a base crop of chickpea was sown with a single row hand drill in 60 cm spaced paired row strips (60/20 cm). In both experiments nitrogen was used as a basal dose @ 30 Kg ha-1 at the time of sowing. In a second experiment phosphorus was applied @ 60 Kg ha-1 as a basal dose at the time of sowing. The results obtained are summarized as follows:-
EXPERIMENT: 1 -Inoculation increased plant height, pods per plant, and seed per pod, net assimilation rate, harvest index, phosphorus uptake, seed protein contents, and seed phosphorus contents, respectively.
-The interactive effect of inoculation and phosphorus on plant height, number of pod bearing branches, number of pods per plant, number of seeds per pod, net assimilation rate, harvest index, seed protein, and seed phosphorus contents was non significant during both the years while the 1000- seed weight was significantly increased during both years.
-Combined application of phosphorus and inoculation increased nodulation, leaf area index, crop growth rate, and total N uptake, biological, and seed yield ha-1 significantly. -Higher seed yield was obtained by seed inoculation and phosphorus application at 90 kg ha-1, which was on a par with 120 Kg ha-1 in 1999-2000, but the interaction was non-significant in 2000-2001.
-All intercrops reduced the economic yield of chickpea to a considerable extent in both years. However, an additional harvest obtained from associated cultures compensated more than the losses in chickpea production, except chickpea + two rows of canola treatment.
-Among the intercropping systems, chickpea grown with one row of lentil gave the maximum seed yield (1832.61 kg ha-1).
-Harvest index of chickpea was also higher in chickpea alone than chickpea grown in association with different intercrops.
-Significantly higher protein and phosphorus content percentage in chickpea seed was obtained in chickpea alone followed by (chickpea + one row of lentil).
-Biological yield, leaf area index, and crop growth rate of chickpea were reduced substantially due to intercropping of wheat, lentil, linseed, and canola compared with sole chickpea, while net assimilation rate was increased substantially due to intercropping of wheat, lentil, linseed’s and canola.
-Maximum total nitrogen and phosphorus uptake was obtained in chickpea alone.
-Land equivalent ratio and area time equivalent ratio in all the intercropping systems except (chickpea + two rows of canola) were higher than that of chickpea alone.
-Competition ratio revealed that chickpea was the dominant crop when it was intercropped with one or two rows of wheat, lentil, and one row of linseed.
-Data on the relative crowding coefficient suggested that chickpea grown in association with one or two rows of wheat, lentil, and two rows of linseed utilized the resources more aggressively than the respective intercrops, which appeared to be dominant. Within intercrops, canola proved to be more competitive.
-Data on aggressivity value revealed that chickpea was the dominant crop when it was intercropped with one or two rows of wheat, lentil, and one row of linseed.
-Substantially higher net field benefit was obtained from the intercropping treatments as compared with the sole cropping of chickpea. On the basis of two years average data, the highest net field benefit of Rs.42761 ha-1 was obtained from chickpea + one row of wheat against the minimum of Rs. 35694 ha-1 from the chickpea alone.
-Marginal analysis revealed that the marginal rate of return increased when chickpea was intercropped with one row of lentil. Similarly, sensitivity analysis showed that the recommendations framed were valid even with fluctuation in input and output prices.