Impact of Rice Nursery Nutrient Management, Seeding Density and Seedling Age on Yield and Yield Attributes

Abstract

To help farmers in the mid hills of Nepal improve their crop management and rice yields, we conducted a study testing different nursery management options and their effect on grain yield and yield components under rainfed conditions. The experiment was conducted in a farmer's field during the cropping season 2009 and 2010 at Sundarbazar, Lamjung, Nepal, using a 3-factor factorial RCB design with 3 replications. The three management factors tested were 1) fertilizer management in the nursery, 2) seeding density, and 3) seedling age at transplanting, using the rainfed lowland rice variety Radha-4. There were eight treatment combinations, consisting of two levels of fertilization (0 and 20:20:0:13 kg NPKS ha −1 at 15 DAS), two levels of seeding density (607 and 303 g·m −2) and two seedling ages (20 and 40 days old). Two years' results showed that top-dressed fertilizer in the nursery had no consistent effect on grain yield. However, lower seeding density (303 g·m , less sterility and higher grain yield. In addition, older seedlings (40 days) produced taller plants, more productive tillers, more filled grains, and a higher grain and straw yield. The interaction analysis between both factors indicated that 40 days old seedling with a low seeding density produced the highest grain yield, both in the drought season 2009 and the high-yielding season 2010. The economic analysis confirmed that the treatment with low seeding density and 40 days old seedlings produced by far the highest net returns and B:C ratio in both seasons, independent of the fertilizer treatment. The combination of these two management components is therefore economically viable and profitable, and can be recommended to farmers. However, the results need to be confirmed for other varieties used by farmers in the region.

Improved nursery management further enhances the productivity of stress-tolerant rice varieties in coastal rainfed lowlands

“…Similarly, Amin and Haque (2009) reported that 35-d-old seedlings were better than younger (15-and 25-d-old) or older (45-d-old) ones. The better performance of older seedlings (35-45-d-old as compared with 25-30-d-old) was also reported by Channabasappa et al (1998), Alam et al (2002), Ella and Ismail (2006), Adhikari et al (2013), Sumon et al (2013), andBhowmick et al (2014) in less favorable conditions. Older seedlings had higher dry biomass and carbohydrate storage at transplanting.…”

“…Mustari et al (2013) found that seedlings from nurseries with low seeding density (25 g m −2 versus 40 g m −2 ) were more vigorous and had a yield advantage ranging from 29% to 141% for different varieties and submergence conditions, with greater response in tall, submergence-intolerant varieties such as Mahsuri. Better stress tolerance and higher yields due to healthy and vigorous seedlings were also reported by TeKrony and Egli (1991), Ella and Ismail (2006), Singh et al (2012), and Adhikari et al (2013).…”

“…Age of seedlings at transplanting is particularly important for areas affected by salinity and floods because younger seedlings are more sensitive to both stresses. Results from drought stress affected areas in the mid-hills of Nepal highlighted the importance of good seedbed management and right seedling age, leading to significantly higher rice yields (Adhikari et al, 2013).…”

Nursery Fertilizer Application Increases Rice Growth and Yield in Rainfed Lowlands with or without Post-Transplanting Crop Stress

“…Furthermore, and importantly, the effects of low nutrient supply in the nursery were not reversed by applying higher rates of fertilizer after transplanting or by transplanting older seedlings. Similarly, Shalaby et al [11], Rajagopalan and Krishnarajan [12] and Panda et al [13] found that nutrient application to nurseries improved rice grain yield while Adhikari et al [7] found no effect of nursery N fertiliser application on post-transplanting growth or yield of rice on a moderately fertile loamy soil in the mid-hills of Nepal.…”

“…Seedlings of advanced age may behave differently in their response to nursery fertilizer application and to post-transplanting stress. Adhikari et al reported that transplanting 40-day-old rice seedlings increased rice yield and effective tiller number in the monsoon season compared to 20-day-old rice seedlings on a loamy, moderately fertile soil in Nepal [7]. By contrast, a number of recent studies, spurred by the interest in the system for rice intensification (SRI), have found increased post-transplanting rice yield from seedlings as young as 10 days compared to those 20 -40 days old [8].…”