Bangladesh-Usda Collaborative Research Program in the Agricultural Sciences

Integrated Nutrient Management for Sustainable Potato Production

in Bangladesh

M. Jahiruddin1, M. A. Rahman2, M. A. Haque3, M. M. Rahman1, and M. R. Islam1

1 Department of Soil Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

2 Soil Resource Development Institute, Regional Laboratory, Rajshahi, Bangladesh.

3 Department of Soil Science, Patuakhali Science & Technology University, Bangladesh

Keywords: Potato, cowdung, poultry manure, compost, INM, soil fertility, crop yield

Abstract

The influence of integrated nutrient management (INM) on potato cultivation (variety Granola, Netherlands origin) was studied through field experiments in the farmers’ plots at 16 sites in the winter season of 2009-10. There were six treatments - absolute control, farmer’s fertilizer practice, 100% recommended dose of chemical fertilizers and the rest fertilizer treatments supplemented with 5 t ha-1 cowdung, 3 t ha-1 poultry manure or 10 t ha-1 compost. The experiments were laid out in a randomized complete block design, with three replications. Integrated use of manure and fertilizer produced significantly higher tuber yield at all sites over only chemical fertilizers use. Effect of INM with compost or poultry manurewas found always better than that with cowdung. Farmers’ practice using high dose of chemical fertilizers in some sites resulted in higher tuber yield, but that was not economically and environmentally viable. Integrated use of fertilizers with cowdung produced on an average about 10% yield increase over 100% chemical fertilizer treatment while fertilizers with poultry manure or compost demonstrated about 25 % yield increase over exclusive fertilizers application. Residual effect of manure is also evidenced in the following rice crops, showing a better performance of compost and poultry manure compared to cowdung. It appeared from another study that bio-slurry with cattle or poultry manure had better effect on potato crop compared to original manure. These studies reveal that for sustenance of soil fertility and crop yield combined application of manure and fertilizer is essential.

INTRODUCTION

Soil fertility depletion is a major constraint to higher crop production in Bangladesh. Increasing cropping intensity (about 200%), use of modern varieties (HYVs & hybrids), cultivation of high biomass potential crops (e.g. maize), nutrient leaching and unbalanced application of fertilizers, with no or little addition of organic manure have resulted in a remarkable nutrient mining from Bangladesh soils (Islam et al., 2008; Jahiruddin, 2006; Rijpma and Jahiruddin, 2004).

Potato is a popular and common vegetable in Bangladesh. Considering area coverage, it has occupied the third position, after rice and wheat. Bangladesh has now 12th position among the world’s potato growing countries and 4th position in Asia after China, Russia and Iran. Unfortunately tuber yield at farmer’s level is very low. A major reason for low tuber yield is unbalanced use of chemical fertilizers, with no or little use of manure.

To stop nutrient mining, it is not justified to just increase the use of inorganic fertilizers, the organic sources of plant nutrients viz. cowdung, poultry manure, compost etc. need to be also considered in the fertilizer schedule. Thus, the present study was undertaken with an objective of improvingpotato yield without incurring loss to soil fertility through efficient organic matter and balanced fertilizer management.

MATERIALS AND METHODS

Field trials were made in the plots of 16 farmers of Kurigram Sadar andUlipur upazilasacross two agro-ecological zones in Bangladesh- Teesta Meander Floodplain and Active Brahmaputra & Jamuna Floodplain, respectively.General soil fertility level is low; the soil pH slightly acidic; the om and N level low to very low; the P & K level low to medium; the Mg level low in some sites; the Zn & B level medium to optimum (Table 1).

There were six treatments, of which 1 was absolute control, 1 was farmer’s usual practice, 1 100% recommended dose of fertilizers (BARC, 2005) and 3 were fertilizers combined with 1 type of locally available manure such as. cowdung, poultry manure and compost. The last three treatments were IPNS basis i.e. fertilizers were supplemented with 5 t ha-1 cowdung, 3 t ha-1 poultry manure or 10 t ha-1 compost to adjust 100% dose of chemical fertilizers. The IPNS calculation was made on the basis of N rate so that some nutrients like P in the manure treatment had exceeded the recommended dose.

Cowdung contained 1.20% N, 0.49% P and 0.56% K, these nutrients contents in poultry manure were 1.90% N, 0.94% P and 0.56% K, and in compost their levels were 0.48% N, 0.25% P and 0.35% K. Full amount of all manure and fertilizers except urea were applied to the plots during final land preparation. Urea was applied in three equal splits - during land preparation and at two crop growth stages. The potato experiments were laid out in a randomized complete block design (RCBD), with three replications. Each unit plot size was 4m x 5m. The lay-out was kept undisturbed in some sites for the next crop (Boro rice) in order to see the residual effect of manures. The second crop in all the 18 plots received an equal and recommended amount of chemical fertilizers.

Potato (Cv. Granola) was planted during the third week of November 2009 and harvested at maturity during the third week of February 2010. Boro rice (cv. BRRI dhan28) was harvested in the 4thweek of February and harvested in the 2ndweek of June. Intercultural operations viz. weeding, earthing-up and irrigation were done whenever required. The yield data were analyzed statistically following F-test and the mean comparisons of treatments were adjudged by DMRT (Gomez and Gomez, 1984).

RESULTS AND DISCUSSION

The effect of the integrated use of manure and fertilizer on the tuber yield of potato (cv. Granola) was found quite pronounced at all 16 sites, the yield being 20-30 t ha-1 (Table 2). Although the yield varied with locations and sites, the treatment effects werealmost same over the sites. In some sites under Kurigram Sadar, the farmer’s practice produced higher tuber yield compared to the recommended fertilizer and fertilizer+manure treatments, in which case the farmers used exceedingly high amount of NPK fertilizers which in terms of economics of fertilzer usewould not be promising.

After harvest of potato, Boro rice (cv. BRRI dhan28) was grown as the second crop. It was grown in eight sites under Kurigram Sadar and Ulipur upazilas. Concerning the second crop, the residual effect of different types of manure was monitored. It showed that in terms of grain yield the compost treatment was the highest, followed by chronologically poultry manure, cowdung and absolute chemical fertilizers (Table 3).

In all sites the crop responded significantly to the fertilizer and manure applications. This result demonstrates that the farmers’ plots were deficient in those nutrients. The soil analysis results also indicated deficiency of some nutrients (Table 1). This shows a good correlation between soil test values and crop yield response.

The IPNS treatments always produced higher crop yield compared to the 100% chemical fertilizer treatment(Table2). Comparing the effect of different types of manure, effect of both compost and poultry manure was better than that of cowdung which can be attributed to the higher supply of nutrients (other than nitrogen) in one hand and slower rate of decomposition rate on the other hand. Some farmers had used fertilizers in potato cultivation at higher rate than the recommendation, which resulted in sometimes higher yield. Nevertheless, this rate of fertilizers may not be economic. Crop yields also varied between locations and also between sites which is due to native soil fertility and/or crop management factors.

A separate field trial was made to examine the effect of INM with cattle or poultry bio-slurry on potato crop. Bio-slurry treatments had a better effect on the crop compared to original manure.

CONCLUSION

The IPNS approach of fertilizer management was found to be effectivefor obtaining higher crop yields at different locations and sites under Kurigram Sadar and Ulipur upazilas. Neither fertilizer nor manure alone can sustain higher and satisfactory crop yield. For sustenance of soil fertility and crop yield, judicious application of manure and fertilizer is essential.

ACKNOWLEDGEMENT

We gratefully acknowledge the financial support provided by the Danish International Development Agency (DANIDA) to carry out this research project

Literature Cited

BARC, 2005. Fertilizer Recommendation Guide. BARC, Soils Pub. 45, Dhaka.

Gomez, K.A. and Gomez, A.A. 1984. Statistical Procedures for Agricultural Research. 2nd Edt. A Wiley Inter-Science Publication, John Wiley and Sons., New York.

Islam, M.S. 2008. Soil fertility history, present status and future scenario in Bangladesh. Bangladesh J. Agric. Environ. (Special issue) 4: 129 -152.

Jahiruddin, M. 2006. Project Completion Report (BAU component I1)- SFFP II. Bangladesh

Agricultural University, Mymensingh.

Rijpma, J. and Jahiruddin, M. 2004. National strategy and plan for use of soil nutrient

balance in Bangladesh. Final Report of Assignment, SFFP-DANIDA.

1

Tables

Table 1. pH, organic matter and nutrients status of soils in different farmers’ fields in

Kurigram Sadar and Ulipur upazils

Kurigram Sadar

Ulipur upazila

1

Table 2. Influence of integrated use of manure and fertilizer on the tuber yield (t ha-1) of

potato in Kurigram sadar and Ulipur upazilas

Kurigram Sadar

Ulipur

In a column, the values having common letter are not significantly different at 5% level by DMRT.

CF = Chemical fertilizers CD = Cowdung PM = Poultry manure

Com = Compost (domestic) FP = Farmer’s practice

T3 - T5 = IPNS basis Potato variety = Granular

Table 3. Residual effect of integrated use of manure and fertilizer on the grain yield (t ha-1)

of Boro rice in the Potato-Boro rice-T. Aman rice pattern

In a column, the values having common letter are not significantly different at 5% level by DMRT.

T3 - T5 = IPNS basis Boro rice variety = BRRI dhan28

.

1