Impact of dry seeding with alternate wetting and drying on rice productivity and profitability in Punjab-Pakistan

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1 Impact of dry seeding with alternate wetting and drying on rice productivity and profitability in Punjab-Pakistan Mann RA 1, Hussain S 1, Saleem M 2 1 Rice Program, National Agricultural Research Centre (NARC), Islambad, Pakistan; riazmann5@gmail.com 2 Nuclear Institute for Agriculture and Biology, Jhang road, Faisalabad Keywords: conventional farmers practice, direct seeding, water saving, tillers, grain yield Introduction In Pakistan, rice is the second largest staple food crop after wheat. It is planted on an area of over 2.88 Mha with total production of 6.87 Mt. Rice in Punjab province is grown by manual transplanting of day old rice seedlings (raised somewhere else) into puddled soil and the fields remain flooded for most of the season. The present rice cultivation system is not very productive, resource-efficient or sustainable. Continuous puddling over the decades has led to deterioration in physical properties of the soil through structural break down of soil aggregates and capillary pores and clay dispersion. Low nitrogen-use efficiency in paddy rice ( 40 %), and low plant population are significant causes of low paddy yield of the traditional production method. The rice crop consumes over 30 % of the available water resources in the country. There is a deficit of Mm 3 water in agriculture which is likely to be doubled in the 2 nd decade of this century. Thus, complete reliance on labour- and water-intensive rice cultivation is not going to be economic in the present scenario. In order to grow more quality food from scarce resources (labour, water, inputs) on marginal/degraded lands, the current rice crop production system must be improved to make it more viable and eco-friendly. Dry seeding with alternate wetting and drying (AWD) water management reduce irrigation water input and labour requirement, and improve the soil for non-rice crops grown in rotation with rice. It entails dry seeding of rice in non-puddled soil, aiming at high yields. Even though transplanting is a popular method among the farming community for rice planting, the cost of labour is high, and it often results in delayed planting, and sub-optimal plant density. Therefore, substitution of transplanting with dry seeding could be advantageous (Johnkutty et al., 2002). Dry seeding with AWD can greatly reduce water losses and labour requirement (Mann et al., 2007). Hence, dry seeding with AWD was tested and demonstrated at several farmers fields during the 2009 and 2010 rice seasons to evaluate effects on crop yield and irrigation input in Punjab, Pakistan. Materials and Methods The demo plots were conducted at 25 locations of three main rice-growing areas viz. Sadhoke (district Gujranwala), Chunian (district Kasur) and Chiniot of Punjab province. The soil of this belt is heavy-textured, poorly drained and saline-sodic. Shortage of canal water is prevalent, and large numbers of tube wells have been installed to supplement the irrigation water for rice crop production. The sites for demo plots were selected along the main route and appropriate branch roads for maximum visibility to have maximum multiplier effect among the farming community. At each site, dry seeded rice with AWD was compared with conventional farmers' practice (puddled, transplanted and continuously flooded rice). A total 135 plots (one acre each) were established. For the dry seeded rice, 15 kg pre-soaked seeds (soaked for h in water), were broadcast onto the surface of the cultivated soil when soil

2 moisture was at field capacity, and then planking was done. At the same time, the rice nursery was sown for transplanting. A basmati rice variety was used at all sites. At some sites, light irrigation was applied 5-6 days after seeding to facilitate germination and plant establishment, depending upon soil moisture and ambient temperature. Otherwise, the first irrigation was applied days after sowing. Subsequent irrigations were applied at 3-5 days interval for one month to promote plant growth and tillering, then the irrigation interval was increased to 7-9 days. Weeds are a major threat to high productivity of dry direct seeded rice crops. A pre-emergence herbicides (e.g. Pendimethalin) was applied immediately after seeding. Then, at days after sowing, when maximum weeds appear the post-emergence herbicide 2.5 liter/ha (Ethoxy sulfuron) was applied. In some fields, one hand weeding (a normal requirement for dry seeded rice with AWD in farmers fields) was done. Recommended agronomic and crop protection practices were applied uniformly to all the plots. Irrigation water to each field was measured through Cut-Throat flumes installed in the main water course to each field. Data on productive tillers, plant height, panicle length, thousand-grain weight and grain yield were recorded and analyzed statistically using STATISTIX software and differences among the treatment means were compared by the least significant differences (LSD) test at the 5% probability level. Results and Discussion Irrigation water saving The dry seeded rice crops used an average of 1410 mm irrigation water against 1850 mm with conventional farmers practice (Table 1), a 25% irrigation water saving. The maximum water saving was recorded at Sadhoke site, on clay soil (with high water-holding capacity and low percolation rate), while the lowest saving was recorded at Chunnian site, on light textured soil.

3 Table 1. Average irrigation water use and saving of dry seeded rice (DSR) compared with farmer practice at 3 sites. Project sites Irrigation water input (mm) % water saving of DSR over farmers practice Farmers practice (puddled, Dry seeded rice transplanted and flooded) Sadhoke (n=52) 2160 a 1450 c 33 Chunian (n=43) 1730 b 1300 d 25 Chiniot (n=40) 1680 b 1470 c 12 Mean Productive tillers and grain yield At all the three sites, dry seeding resulted in more productive tillers, with site averages of /m 2 and an average increase of 48.6% over puddled transplanted rice (Table 2). These results are consistent with those of Wiangsamut et al. (2006) and Ullah et al. (2007), who found more productive tillers in dry seeded than transplanted rice. Average yield of dry seeded rice was 5.35 t ha -1, compared to 4.20 t ha -1 with conventional farmers practice, a 27.3% increase (Table 3). These results are also consistent with those of Ullah et al. (2007), Wiangsamut et al. (2006) and Gangwar et al. (2008) who recorded maximum rice yield from dry seeding. The partial budget analysis showed that dry seeding of rice generated Rs. 32,550/ha (US$ 383/ha) more than the conventional rice production practice. Thus dry seeding with AWD can help overcome the problems of low plant density leading to low yield, and scarcity of water and labour, in the current rice farming system, leading to enhanced land and water productivity and farmers income. Table 2: Average productive tillers of dry seeded rice (DSR) compared with farmer practice at 3 sites. Project sites Productive tillers/m 2 % increase of DSR over farmers Farmers practice (puddled, Dry seeded rice practice transplanted and flooded) Sadhoke (n=52) 287 b 452 a 57 Chunian (n=43) 235 c 397 a 69 Chiniot (n=40) 310 b 388 a 25 Mean Table 3: Average grain yield of dry seeded rice (DSR) compared with farmer practice at 3 Sites.

4 Project sites Rice yield (t/ha) % increase in DS over Farmers practice (puddled, Direct dry seeded rice farmers practice transplanted and flooded) crop (DS) Sadhoke (n=52) 4.0 b 6.0 a 48 Chunian (n=43) 3.5 b 4.6 b 31 Chiniot (n=40) 5.1 a 5.5 a 8 Mean Figure 1: Dry seeded rice crops at farmers fields in Sadhoke and Chiniot during 2009.

5 References Gangwar, K.S., O.K. Tomar and D.K. Pandey Productivity and economics of transplanted and direct-seeded rice (Oryza sativa) based cropping systems in Indo- Gangetic plains. Ind. J. Agri. Sci. 78(8): Johnkutty, I., G. Mathew and J. Mathew Comparison between transplanting and direct-seeding methods for crop establishment in rice. J. Tropic. Agri. 40: Mann, R.A., S. Ahmad, G. Hassan and M.S. Baloch Weed management in direct seeded rice crop. Pak. J. Weed Sci. Res. 13(3-4): Ullah, M.A., S.A.R. Zaidi, A. Razzaq and S.D.H. Bokh Effect of planting techniques (Direct seeding Vs. Transplanting) on paddy yield in salt-affected soil. Int. J. Agri. Biol. 09(1): Wiangsamutt, B., C.T. Mendoza and A.T. Lafarge Growth dynamics and yield of rice genotypes grown in transplanted and direct-seeded fields. J. Agri. Tech. 2(2):