Bangladesh Agron. J. 2022, 25(1): 97-103 SUSTAINABLE SOIL MANAGEMENT FOR NUTRITION SENSITIVE AGRICULTURE THROUGH MICRONUTRIENT INCLUSION IN BORO RICE CULTIVATION P.K. Biswas, S. Samia and S. Shome Department of Agronomy, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh Corresponding E-mail: parimalbiswas@hotmail.com (Received: 25 May 2022, Accepted: 11 July 2022) Keywords: Zinc, boron, organic manure, foliar spray, rice Abstract The experiment was conducted in Boro season, 2020-21 to compare the performance of fortified rice variety BRRI dhan84 with non-fortified mega variety BRRI dhan89 and their suitable combinations for maximum growth and yield. Treatments were: two rice variety viz., i) BRRI dhan84 (V1) and ii) BRRI dhan89 (V2) in the main plot and seven different fertilizer management viz., i) No fertilizer (F1), ii) Recommended NPKS (RFD) with Zn as basal (F2), iii) RFD + Zn as foliar at anthesis (F3), iv) RFD + Zn & B as foliar at anthesis (F4), v) 50% RFD + 50% Cowdung as basal (F5), vi) 50% RFD + 50% Cowdung + Zn & B as basal (F6) and vii) 50% RFD + 50% Cowdung as basal + Zn & B as foliar at anthesis (F7) in the sub-plot. The experiment was laid out in a Split-plot design having 3 replications. No significant variations observed between the two varieties for almost all the studied characters except filled grains panicle-1 where the variety BRRI dhan89 showed higher number of grains (116.14) than the other variety. Foliar application of zinc and born (F4) gave the highest plant height (102.54 cm), effective tillers hill-1 (12.83) that similar (13.00) with F2 (recommended NPKS with Zn as basal), panicle length (25.91 cm), 1000-grain weight (23.58 g), grain yield (7.67 t ha-1), biological yield (14.85 t ha-1) and harvest index (51.69%). The interaction of V2F4 and V1F4 resulted superior response for almost all the studied parameters. Foliar application of zinc and boron (F4) along with RFD increased 8.79 and 27.45% yield in BRRI dhan89 compared to that of foliar (F3) and basal (F2) application of zinc, respectively that was 17.11 and 26.77% for the other rice variety BRRI dhan84. Introduction Rice (Oryza sativa L.) is the staple food in Bangladesh and accounting for approximately 78 percent of the country’s total net cropped areas cultivation. The country achieves an autarky to meet up the rice demand for its 169.04 million peoples from 11.55 million hectares of cultivated gross area (Kabir et al., 2020; Nasim et al., 2021). Rice provides about 75% of the calories and 55% of the protein in the average daily diet of the people of Bangladesh and contributes 18% to GDP (Bhuiyan et al., 2002). Grain quality has always been an important consideration in rice variety selection and development. Fortified rice varieties are rich in micronutrients like zinc and iron. Nutrition-sensitive agriculture is a food-based approach to agricultural development that puts nutritionally rich foods to overcome malnutrition and micronutrient deficiencies. Micronutrients provided by soils are crucial for plant development and growth. Nutrient mining occurs when crops take out a high proportion of the nutrients available in the soil, leaving a nutrient imbalance that threatens the sustained provision of food and ecosystem services. Furthermore, good nutrition is achieved through healthy and balanced diets, composed of foods with adequate nutritional composition. Exploring different soil management practices can help increase the nutritional content of crops, as many are directly affected by the nutritional status of the soil. FAO and ITPS (2015) have demonstrated the extent of soil fertility has suffered from unsustainable management practices. Rates of malnutrition in Bangladesh are among the highest in the world. More than 54 %t of preschool-age children, equivalent to more than 9.5 million children, are stunted, 98 Biswas et al. 56 percent are underweight and more than 17 % wasted. Bangladeshi children also suffer from high rates of micronutrient deficiencies, particularly vitamin A, iron, iodine and zinc deficiency. Improving nutrition through soils can have a significant impact on malnutrition in Bangladesh. This population- wide zinc deficiency is one key reason why stunting affects 41% of children in Bangladesh aged under five years (Rahman et al., 2016). Cultivation of MV and hybrid varieties of different crops is deteriorating soil fertility status of most Bangladesh soil day by day due to exhaustive nature of those varieties. As a consequences new nutrient deficiency in soil is emerging. Chronologically N, P, K, S, Zn and B deficiencies have arisen in Bangladesh soils (Islam, 2008). Some reasons of micronutrient deficiency in Bangladesh were highlighted by Jahiruddin and Islam (2014) and those are organic matter depletion, unbalanced use of fertilizers, minimum or no use of manure, high cropping intensity, high pH (e.g. calcareous soils), nutrient leaching and light textured soils (Jahiruddin and Islam, 2014). Rice bio-fortified with zinc (zinc rice) could help the critical gap by delivering up to 90% of their daily dietary requirements of zinc naturally (Bashar and Miah, 2016). Rice var. BRRI dhan84 composes of zinc which may scale up its potentially-competitive agronomic characteristics along with another non-fortified variety. Kaer et al. (2020) also reported that the zinc enriched BRRI dhan84 is a superb variety for cultivating in the dry (Boro) season and farmers can be economically benefited. The study was therefore undertaken to compare the performance of fortified rice var. BRRI dhan84 with BRRI dhan89 and to determine the suitable fertilizer management. Materials and Methods The experiment was conducted during the December 2020 to June 2021 at the Agronomy field of Sher- e-Bangla Agricultural University, Dhaka. The seeds of Boro rice var. BRRI dhan84 and BRRI dhan89 were used as plant materials and the seeds were collected from Bangladesh Rice Research Institute (BRRI), Joydebpur, Gazipur. The basal recommended dose i.e., urea, TSP, MoP, Zn and B and with cowdung were used in the experiment as per treatment. The whole amount of all fertilizers except urea along with cowdung was applied as a basal dose during final land preparation. The urea fertilizer was applied as four equal splits at 10, 20, 30 and 40 days after transplanting (DAT). The foliar application of Zn and B were applied as per treatment before anthesis. The sprouted seeds of two rice varieties were sown in the nursery bed on 05 December, 2020 from which 35 days old seedlings were transplanted in the main field on 10 January, 2021 maintaining 20 cm x 20 cm spacing. The experiment was laid out in a Split-plot design with three replications. The treatments were two variety viz., i) BRRI dhan84 (V1) and ii) BRRI dhan89 (V2) in the main- plot and seven different fertilizer management viz., i) No fertilizer (F1), ii) Recommended NPKS (RFD) with Zn as basal (F2), iii) RFD + Zn as foliar at anthesis (F3), iv) RFD + Zn & B as foliar at anthesis (F4), v) 50% RFD + 50% Cowdung as basal (F5), vi) 50% RFD + 50% Cowdung + Zn and B as basal (F6) and vii) 50% RFD + 50% Cowdung as basal + Zn and B as foliar at anthesis (F7) in the sub-plot. Water was ensured to the field throughout the growing season up to 10 days before harvesting. Two hand weedings were done for all the treatments on 30 and 45 DAT. The field was infested by different insects and diseases those controlled by applying appropriate ways in time. Five hills per plot was randomly selected for collecting plant height, number of tillers hill-1 and SPAD value at stipulated dates. The yield and yield attributes were recorded. The grain yield and straw yield were recorded at 12 % moisture level. Statistical analyses were done by using the Crop Stat computer package and the mean differences among the treatments were compared by least significant difference test at 5 % level of significance following Gomez and Gomez (1984). Results and Discussion Effect of variety Sustainable Soil Management for Nutrition Sensitive Agriculture 99 All the studied characters showed non-significant variation between the two varieties except number of filled grains panicle-1 where BRRI dhan89 (116.14) showed higher response compared to that of BRRI dhan84 (89.47) (Table 1 and Table 2). The mega var. BRRI dhan89 resulted 29.81% higher number of filled grains panicle-1 than the other biofortified variety BRRI dhan84. Numerically the variety BRRI dhan89 showed 7.36% higher grain yield than BRRI dhan84. Similar variation of filled grains panicle-1 among rice varieties was also reported by Khatun et al. (2020).The number of grains panicle-1 is mainly determined by the panicle architecture, including panicle length and the number and length of primary, secondary and higher order branches (Sakamoto and Matsuoka, 2008; Kovi et al., 2011). Table 1. Varietal and fertilizer response on different crop characters of Boro rice Treatments Plant height (cm) Effective tillers hill-1 (No.) Panicle length (cm) Filled grains panicle-1 (No.) Unfilled grains panicle-1 (No.) Variety V1 96.05 12.14 25.36 89.47b 18.43 V2 97.60 10.86 26.09 116.14a 16.71 LSD(0.05) NS NS NS 13.394 NS CV (%) 5.38 14.51 4.92 9.81 17.54 Fertilizer management F1 86.74d 9.17c 24.75b 96.50ab 13.83c F2 99.40abc 13.00a 25.49ab 98.83ab 21.17ab F3 99.73ab 12.83a 25.75a 108.17ab 18.50abc F4 102.54a 12.83a 25.91a 105.67ab 22.83a F5 97.67bc 11.50ab 25.93a 105.33ab 16.17bc F6 94.44c 10.33bc 26.14a 92.33b 14.83c F7 97.25bc 10.83abc 25.91a 112.83a 15.67c LSD(0.05) 4.297 2.183 1.020 20.307 6.284 CV (%) 3.72 15.93 3.33 16.58 30.01 Interaction V1F1 84.19e 9.67cde 24.25c 85.33cde 11.33d V1F2 100.14ab 14.00a 25.24bc 76.00de 26.67a V1F3 97.77abc 13.00ab 25.58abc 96.67a-e 17.00bcd V1F4 102.02ab 12.67abc 26.09ab 92.00b-e 24.33ab V1F5 98.23abc 13.67a 25.71ab 97.00a-e 15.00cd V1F6 92.81cd 10.33b-e 25.43abc 75.00e 16.33bcd V1F7 97.20abc 11.67a-e 25.22bc 104.33a-d 18.33a-d V2F1 89.29de 8.67e 25.66abc 107.68abc 16.33bcd V2F2 98.65abc 12.00a-d 25.73ab 121.67a 15.67bcd V2F3 101.70ab 12.67abc 25.92ab 119.67ab 20.00a-d V2F4 103.05a 13.00ab 25.73ab 119.33ab 21.33abc V2F5 97.11abc 9.33de 26.15ab 113.67abc 17.33bcd V2F6 96.08bc 10.33bcde 26.84a 109.67abc 13.33cd V2F7 97.29abc 10.00bcde 26.59ab 121.33a 13.00cd LSD(0.05) 6.077 3.088 1.442 28.719 8.887 CV (%) 3.72 15.93 3.33 16.58 30.01 V1 = BRRI dhan84, V2 = BRRI dhan89, F1 = No fertilizer, F2 = RFD with Zn as basal, F3 = RFD with Zn as foliar, F4 = RFD with Zn and B as foliar, F5 = 50% RFD & 50% cowdung, F6 = 50% RFD & 50% cowdung with Zn and B as basal, F7 = 50% RFD & 50% cowdung with Zn and B as foliar Effect of fertilizer management The highest plant height (102.54 cm) at harvest, highest number of effective tillers hill-1 (12.83), 1000- grain weight (23.58 g), grain yield (7.67 t ha-1), biological yield (14.85 t ha-1) and harvest index (51.69 %) was recorded from the F4 (RFD with Zn and B as foliar) treatment but the lowest result given by F1 (No fertilizer) treatment for most of the studied parameters (Table 1 and Table 2). Application of RFD (NPKS) as per FRG (2018) but zinc and boron as foliar application during anthesis (F4) gave 27.20 % and 74.32 % higher grain yields than F2 (RFD with Zn as basal dose) and F1 (No fertilizer) treatments respectively. Significant effect of zinc on plant height of rice was reported by Uddin et al. (1997), https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6514245/#B41 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6514245/#B21 100 Biswas et al. effective tillers hill-1 by Rahman et al. (2008), grain yield by Islam et al. (1997), Wasaya et al. (2017) and Azad (2018) and straw yield by Islam et al. (1997). Interaction of variety and fertilizer management The treatment combination of V2F4 (BRRI dhan89 and RFD with Zn and B as foliar application) showed the highest plant height (103.05 cm), grain yield (7.80 t ha-1)and biological yield (15.31 t ha-1) compared to that of other interactions whereas the highest number of effective tillers hill-1 (14.00) by V1F2, panicle length (26.84 cm) by V2F6, number of filled grains panicle-1 (121.67) by V2F2, number of unfilled grains panicle-1 (26.67) by V1F2, 1000-grain weight (23.83 g) by V2F6, straw yield (8.11 t ha-1) by V2F3 and harvest index (52.36 %) by V1F4 treatment combinations (Table 1 and Table 2). The lowest parameters were recorded from V1F1 (BRRI dhan84 and no fertilizer application) interactions. Recommended fertilizer dose (RFD) with zinc and boron as foliar spray (F4) gave 76.06 % and 72.71 % higher yield compared to their respective control (F1) of BRRI dhan89 (V2) and BRRI dhan84 (V1) respectively whereas 27.45 % and 26.77 % higher than F2 (RFD with zinc as basal dose). Zinc being essential nutrient plays a significant role in stomatal regulation and reducing the tensions of less water by creating ionic balance in plants system (Baybordi, 2006) and is involved in various physiological processes such as synthesis of protein and carbohydrates (Yadavi et al., 2014). Similarly, B application improves growth, and enhances stress tolerance in plants and improves grain production (Hussain et al., 2012). Both Zn and B play an important role in the basic plant functions like photosynthesis, protein and chlorophyll synthesis (Cakmak, 2008). Table 2. Grain weight, yield and harvest index of Boro rice affected by variety and fertilizer management Treatments 1000-grain wt. (g) Grain yield (t ha-1) Straw yield (t ha-1) Biological yield (t ha-1) Harvest index (%) Variety V1 21.64 5.98 6.72 12.70 46.88 V2 22.34 6.42 7.25 13.66 46.79 LSD(0.05) NS NS NS NS NS CV (%) 7.90 9.21 26.19 17.66 10.09 Fertilizer Management F1 20.57d 4.40e 6.92abc 11.32e 39.05d F2 20.98cd 6.03c 7.31a 13.34cd 45.34c F3 21.42cd 6.80b 7.48a 14.28ab 47.81bc F4 23.58a 7.67a 7.19ab 14.85a 51.69a F5 23.33ab 6.86b 7.01abc 13.87bc 49.45ab Sustainable Soil Management for Nutrition Sensitive Agriculture 101 Treatments 1000-grain wt. (g) Grain yield (t ha-1) Straw yield (t ha-1) Biological yield (t ha-1) Harvest index (%) F6 22.13abc 6.10c 6.63bc 12.73d 47.91bc F7 21.92bcd 5.54d 6.37c 11.91e 46.61bc LSD(0.05) 1.474 0.402 0.636 0.664 2.924 CV (%) 5.62 5.45 7.65 4.23 5.24 Interaction V1F1 19.80e 4.36h 6.86bc 11.22g 39.02e V1F2 21.70b-e 5.94ef 6.97bc 12.91de 46.04cd V1F3 20.63de 6.43de 6.85bc 13.27d 48.45a-d V1F4 23.47ab 7.53ab 6.87bc 14.40ab 52.36a V1F5 23.33abc 6.60cd 6.83bc 13.42cd 49.11abc V1F6 20.43de 5.73fg 6.40c 12.12efg 47.30bcd V1F7 22.13a-d 5.29g 6.28c 11.57fg 45.86cd V2F1 21.33cde 4.43h 6.98bc 11.41fg 39.07e V2F2 20.26de 6.12def 7.65ab 13.77bcd 44.63d V2F3 22.20a-d 7.17bc 8.11a 15.28a 47.17bcd V2F4 23.70ab 7.80a 7.50ab 15.31a 51.02ab V2F5 23.33abc 7.13bc 7.18bc 14.32bc 49.78abc V2F6 23.83a 6.47de 6.86bc 13.33d 48.52a-d V2F7 21.70b-e 5.79fg 6.45c 12.24ef 47.35bcd LSD(0.05) 2.084 0.569 0.900 0.940 4.136 CV (%) 5.62 5.45 7.65 4.23 5.24 V1 = BRRI dhan84, V2 = BRRI dhan89, F1 = Control, F2 = RFD with Zn as basal, F3 = RFD with Zn as foliar, F4 = RFD with Zn and B as foliar, F5 = 50% RFD & 50% cowdung, F6 = 50% RFD & 50% cowdung with Zn and B as basal, F7 = 50% RFD & 50% cowdung with Zn and B as foliar Conclusion Based on the results of the study, it may be concluded that the fortified Boro rice variety BRRI dhan84 has the ability to produce similar yield to other mega variety BRRI dhan89. Foliar application of zinc and boron during anthesis along with recommended fertilizer (NPKS) showed higher yield compared to that of basal application of zinc & with NPKS. The recommended fertilizer dose (NPKS) of Boro rice with zinc and boron as foliar spray (F4) during anthesis gave 76.06 % and 72.71 % higher yield compared to their respective control (F1) of BRRI dhan89 (V2) and BRRI dhan84 (V1) respectively whereas 27.45 % and 26.77 % higher than F2 (NPKS with zinc as basal dose). However, to reach a specific conclusion and recommendation, experiments with different levels of other micronutrients need to be repeated with more varieties and in different Agro-ecological zones. Acknowledgement The author gratefully acknowledged the Ministry of Science and Technology, Govt. of the People’s Republic of Bangladesh for providing financial support under Special Allocation fund to conduct the study. References Azad, M.A.K. 2018. 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