Abstract
Six experiments were conducted at Burirhat, RARS, BARI, Rangpur during July 2009-12 to
assess the productivity of selected patterns for the highest yield unit¹ area in sustainable soil
fertility through cultural manipulations viz. date of sowing, variety, fertilization and irrigation. The first experiment consisted of eight cropping patterns. All managements were
done as per BARC recommendation. Among these patterns, the highest total potato equivalent yield and GM of C₁ were 80.70 t ha-1 and Tk. 560633 ha-1 and 53.51 t ha-1 and Tk.
379615 ha-1 of C2 cropping patterns, respectively. The TC and BCR were found to be Tk.
246367 ha-1 and 3.28 for C₁ and Tk.155485 ha-1 and 3.44 for C2 cropping patterns, respectively. These two patterns were found to be the best patterns. The second and third experiment
verified the best sowing date and variety of C₁ and C2 cropping patterns. The highest GR and
BCR were found Tk. 674533 ha-1 and 3.66 of C1 and Tk. 439063 ha-1 and 3.72 of C2 cropping
patterns, respectively compared to that of first experiment results. Here, the difference of total
cost of first and second experiments were only Tk. 5950 ha-1 but, GM and BCR were increased
i.e. Tk. 186100 ha-1 and 0.38 in C₁ and Tk. 59448 ha-1 and 0.28 in C2 cropping patterns. Here,
there found a little difference of total cost of the both experiments. But the GM and BCR were
increased due to shifting of sowing date from 5 Oct. to 13 Oct. and inclusion of variety BARI
Alu - 13 instead of local variety. The fourth and fifth experiments were done to find out the
fertilizer doses and irrigations. The experimental results showed that IPNS dose and three
time irrigations for C1 and C2 cropping patterns performed the best where six fertilizer doses
and three time irrigations were as treatments. As a result, the highest GM and BCR were
obtained by Tk. 770353 ha-1 and 4.00 in C1 and Tk. 547115 ha-1 and 4.43 in C2 cropping
patterns. It was found that the TC of both the patterns were little bit increased but the GM
and BCR were increased Tk. 95820 ha-1 and 0.34 in C1 and Tk. 108052 ha-1 and 0.71 in C2
cropping patterns, respectively due to use of IPNS fertilizer dose and three time irrigations.
Three irrigations and IPNS treatment performed the best than earlier experiment. Again, the
sixth experiment, all managements were same as that of fourth and fifth experiments but only
difference was tuber spacing in first crop potato of C1 and C2 cropping patterns. Here, its spacing was 50 cm × 20 cm. For this cause, GM and BCR were increased to Tk. 20500 ha-1 and
0.06 for C1 and Tk. 26000 ha-1 and 0.12 for C2 cropping patterns, respectively. But after
completion of the sixth experiment, the highest GM was found to be Tk. 790853 ha-1 of C1 and
Tk. 573115 ha-1 of C2 cropping patterns that means extra benefit was Tk. 230220 ha-1 for C₁ and
Tk. 193500 ha-1 for C2 cropping patterns. So, after research the following recommendations
were made a) the best patterns i) C₁ and C2 cropping patterns, b) the best sowing date 13 October
and BARI Alu-13 for first potato crop, 15 December and, BARI Alu-13 or Asterix for second
potato, 20 January and BARI Hybrid Maize-6 for maize crop, 20 April and BARI Mung-6 of mungbean crop and 10 July and BINA dhan-7 of T. Aman rice crop for C1 cropping pattern
and 13 October and BARI Alu-13 of first potato, 15 December and BARI Gom-26 of second
crop wheat, 20 April and BARI Mung-6 of mungbean crop and 10 July and BINA dhan-7 of T. Aman rice crop for C2 cropping pattern, c) Fertilizer dose @ i) 110-10-65-12-0-4-1.2-8000, ii) 110- 5-33, iii) 210-20-86-19-0–4-2, iv) 26-11-28-14-0-0-1.2 and v) 85-6-24-7-1 kg ha-1 of all crops for C₁ cropping pattern and @ i) 110-10-65-12-0-4-1.2-8000, iї) 130-12-72-12-0-2-1, iii) 26-11-28-14-0-
0-1.2 and iv) 85-6-24-7-1 kg ha-1 N-P-K-S-Zn-Mg-B-CD of all crops for C2 cropping pattern, d)
spacing 50 cm x 20 cm and cut tuber of first potato of both the cropping patterns and e) two
irrigations for first potato and 3 irrigations for all crops of both the cropping patterns. The soil fertility status was not deteriorated rather a little bit improved after completion of both the cropping patterns due to use of mungbean and IPNS fertilizer.