How to establish a maize crop on water logged soil?
How to establish a maize crop on water-logged soil?
How to establish a maize crop on water-logged soil
If there is a possibility of an existing cropping pattern being disrupted by delayed sowing time due to heavy rain or tidal flood, how should you establish your maize crop on proper time? The following idea could be one of the alternatives!
Ø Sow your maize seeds using dense seed rate on a piece of seed bed prepared on high land
Ø At seedling’s 8- 10 days ago, make ridges along the rows following the optimum row-to-row distance in the mainland where your maize crop is to be grown
Ø Uproot the maize seedlings and transplant them on the ridge following the recommended plant-to-plant distance in each row
Ø After 7-8 days of transplanting, side-dress fertilizers (as recommended) and mix them well with the soil carefully so that establishing seedlings do not get damaged. In case field capacity not yet reached, dibble fertilizers (mixed) between adjacent seedlings in each rows following the recommended fertilizer dose
Ø Remove weeds as and when it becomes necessary
Ø Provide supplemental irrigation when there is a prolonged drought
Maize is the third most important cereal crop after rice and wheat in Bangladesh (BBS, 2011). It grows all over countries but mostly concentrates in the cropping system of the north-western and western regions (Monayem et al., 2014; Rahman et al., 2016). Both its area and production increased sharply since 2001 (Fig. 1). This crop in Bangladesh fits in the cropping system of rainy season rice (T aman rice) – maize - summer crops, the maize grown in winter (Sept-Feb) in this rice-based cropping system. This is also the major cropping pattern with maize all over the country. However, when grown in winter it competes with other winter crops predominately winter rice (boro rice) wheat, pulses, and oilseed crops. As these crops are the sources of human food, initiatives are being taken to grow maize in summer. Farmers also are being encouraged to grow this crop in summer.
Figure 1 shows the sharp increase in maize yield from 2001 in Bangladesh
Although the average yearly rainfall in Bangladesh is 2460 mm, it is not well distributed either spatially or temporally. The winter season is almost dry with scanty rainfall and most of the upland crops are grown based on the stored soil moisture and sometimes using supplemental irrigations. Summer in Bangladesh predominates with rain. The rainfall initiates in the month of March at a lower magnitude (av. 50 mm), while medium rainfall occurs in the month of April- May (100-250 mm) and is heavy in the month of June to August (450-550 mm). After that, it starts declining with a medium level of rainfall in the months of Sept-Oct (200-270 mm). The rainfall almost ceases in Nov (below 50 mm) and almost there is no rainfall in the months of Dec-February (Fig. 2).
Figure 2 shows the monthly distribution of rainfall in Bangladesh in a normal year (Shahid and Khairulmaini, 2009)
Rain in Bangladesh is neither ever-lasting nor continuous. When starts, it lasts for 10 minutes to a few hours. Sometimes it happens almost continuously even for a couple of days. Under such conditions, the lowlands are inundated. Further, there may be an elongated drought between two adjacent heavy showers. Again the rainfall varies from region to region.
Maize and other upland crops are grown in medium to highlands. In general, these lands do not suffer from severe waterlogging, but under poor drainage conditions coupled with the occurrence of heavy rainfall, the medium to high lands become inundated even for some days causing total failure of the crops. Once undergoes heavy showers it takes one week to 15 days to attain field capacity for the preparation of the land. If there is another heavy shower before attaining the field capacity the medium lands become unfit to grow any crop as these lands may not dry even in a month or more. Such an elongated heavy shower frequently causes delays in sowing summer crops including maize. This situation makes farmers to retain their lands fallow removing one to several weeks from the cropping season transforming the three-crop cropping system to a two-crop cropping system resulting in the failure of growing one crop from the existing cropping pattern.
Winter crops are harvested in the months of Feb to April. Delayed sown maize in the summer may undergo heavy showers in its vegetative stage. If waterlogging occurs immediately after sowing seeds fail to germinate. Water logging at the seedling stage causes seedling death if the water logging conditions elongate. So it is important to innovate technology to ensure on-time sowing and establish a maize crop on lands that are prone to waterlogging to have a stable cropping pattern. It has been reported that maize can tolerate water logging conditions to even up to 10 days. However, the extent of survival of the maize plants and yield loss depends on the length of the water logging period and the crop’s growth stage. The crop may not survive if water logging happens at the seedling stage (Ren et al., 2014). It was observed that if the plant’s base does not go under water it can escape water logging for a longer period. This makes the possibility of establishing a maize crop even if water logging exists in the field for a certain duration.
In an observation trial, this phenomenon was evaluated on the Sher-e-Bangla Agricultural University farm. Seeds of a white maize var. Suvra were sown on July 8, 2016, in a seed bed at the rate of 0.25 Kg/m2. Seeds germinated in 4 days. A medium land was selected where the soil was almost at saturation level after cessation of rain. Fifteen cm high ridges were prepared 70 cm apart. Seedlings from the seed bed were uprooted and transplanted 25 cm apart on each ridge on July 21, 2016 (Plate 1).
Fifteen days after transplantation all the fertilizers at recommended rates and one-third of urea were side-dressed and weeds were cleaned (Plate 2). At 30 days after transplantation first installment of urea fertilizer was applied (Plate 3). Again at 55 days after transplantation, second /last installment of urea was applied (Plate 4). At this stage, the crop had its first tassel.
Plate 1 showing maize seedlings transplanted on ridges on saturated soil
Plate 2 showing the maize crop established on water-logged soil (fertilized at 15 days after transplantation)
Plate 3 shows the maize crop at 30 days after transplantation after the first top dressing of urea fertilizer, the seedling was transplanted and established on water-logged soil
Plate 4 shows the maize crop at 55 days after transplantation after the second top dressing of urea fertilizer, the seedling was transplanted and established on water-logged soil. At this stage, plants started tasselling
After transplanting seedlings, the plot was not irrigated as there happened seasonal rains after some unequal intervals. Due to ridging, the heavy rain did not inundate the base of the plants only submerged underneath furrows and half of the ridge height. However, within a day or two the standing water in the field drained away either through a poor drainage system or leaching downward leaving the surface of the soil saturated for further two to three days. The almost same pattern of soil moisture prevailed following each occurrence of heavy rain after a certain interval. Several consecutive showers occurred until tasselling (as reported now) with intervals of 4 to 10 days without rainfall. However, in the case of the occurrence of delayed rain there happened drought stress in the field (as was seen visually) resulting in wilting in some of the plants. During the recovery stage of seedlings, the field was severely infested by different wetland weeds (Plate 5).
Plate 5 showing the weed-infested maize field established by seedling transplantation at eight days after transplantation. The picture was taken one day after a heavy shower
This study was simply of observational one without taking no data on rainfall, soil moisture or phenotypic and physiological plant parameters. So, before adopting the technology it should be refined by doing a series of researches to optimize the height of the ridge, fertilizer application, length of water logging tolerable to plant and water management.
References
BBS. 2011. Statistical Yearbook of Bangladesh. 2011. Bangladesh Bureau of Statistics (BBS). Parishankhyan Bhaban, E-27/A, Agargaon. Sher-e-Bangla Nagar, Dhaka-1207
M.A. Monayem Miah, Tanvir M.B. Hossain1 and Ranjit Kumar. 2014. Maize Production in Bangladesh: Way towards Self-sufficiency. Paper presented in 12th Asian Maize conference and expert consultation on Maize for food, feed, nutrition, and environmental security, 30 Oct-1 Nov, Bangkok, Thailand.
Ren, B., Zhang, J., Li, X., Fan, X., Dong, S., Liu, P., and Zhao, B. 2014. Effects of waterlogging on the yield and growth of summer maize under field conditions. Can. J. Plant Sci. 94: 23–31.
Sanzidur Rahman, Mohammad Mizanul Haque Kazal, Ismat Ara Begum, and Mohammad Jahangir Alam.2016. Competitiveness, Profitability, Input Demand and Output Supply of Maize Production in Bangladesh – an open access article published by MDPI, Basel, Switzerland. file:///E:/User%20acer/Desktop/agriculture-06-00021.pdf
Shamsuddin Shahid and Osman Salleh Khairulmaini. 2009. Spatio-Temporal Variability of Rainfall over Bangladesh during the Time Period 1969-2003. Asia- Pacific Journal of Atmospheric Sciences, 45, 3, 2009, p.375-389
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