Effect of Green Bean (Phaseolus vulgaris L.) Intercropping with Potato (Solanum tuberosum L.) On Growth Indices, Yield and Total Land Output in Different Nitrogen Levels

Low yield and total land productivity are the main challenges related to agriculture in developing countries. Crop diversification can help reduce these challenges by introducing legumes in intercropping. Therefore, evaluation of the effects of green bean intercropping with potato (Agria cultivar) on physiological indices, yield and total land output (TLO), were important objectives of this study.

Experiment was conducted at the Agricultural Research Station, Faculty of Agriculture, Bu-Ali Sina University in 2016 growing season. Experiment was laid out as a factorial based on randomized complete block design with three replications. Four planting patterns including sole cropping of potato (M1), cropping green bean between rows of potato (M2), cropping green bean on rows of potato (M3) and cropping  green bean between and on rows of potato (M4) were applied in combination with three levels of nitrogen fertilizer (N0, N80 and N160: 0, 80 and 160 kg N.ha-1, respectively).

The results showed that the highest above ground dry matter accumulation (529 g.m-2) and leaf area index (4.86) were obtained at M1×N160 tretment. The highest crop growth rate (21.72 g.m-2.day-1) was achieved at M2 treatment. Maximum tuber dry matter accumulation (877 g.m-2), tuber growth rate (24.50 g.m-2.day-1), and tuber yield (42.48 t.ha-1) were obtained at M2×N160 treatment. In green bean, the highest dry matter accumulation, LAI, CGR and number of green pods per plant were obtained from M2×N80 treatment. At the canopy level, the highest accumulation of dry matter, LAI, LER and TLO were observed at M2×N80 treatment. Treatment of M2×N80 in comparison with M1×N0 treatment (sole cropping of potato without nitrogen consumption), increased TLO up to 43 percentage.

The cultivation of green beans between rows of potato and the application of 80 kg of nitrogen per hectare, in addition to creating biodiversity and ecosystem stability, causes maximum land productivity.