Effects of nutrient elements on yield, nitrogen use efficiency and grain quality of paddy rice in andosol

Effects of Nutrient Elements on Yield, Nitrogen Use Efficiency and Grain Quality of Paddy Rice in Andosol September 2020 PHAN THI THUY Effects of Nutrient Elements on Yield, Nitrogen Use Efficiency and Grain Quality of Paddy Rice in Andosol A Dissertation Submitted to the Graduate School of Life and Environmental Sciences, the University of Tsukuba in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Agricultural Science (Doctoral Program in Biosphere Resource Science and Technology) PHAN THI THUY Abstract Overuse of fertilizer and unbalanced NPK application rates leads to a yield decrease in rice production systems Appropriate nutrient management is one of the most important factors for improving rice yield and maintaining sustainability Nitrogen use efficiency (NUE), which relates both to production quantity and environmental safety, is the important index used to evaluate crop production systems Trends in reduction of NUE have been reported due to unbalance between nitrogen (N) application and crop demand Improving NUE becomes an urgent requirement in crop production Not only N, but also other fertilizers such as phosphorus (P) and potassium (K) may affect NUE but have less been studied On the other hand, consumers pay more attention to rice quality, requiring researchers should also focus on enhancing grain quality under different nutrient elements This research aimed to elucidate role of essential nutrient elements on rice yield, NUE and grain quality Effects of N, P, K, Si and compost (Co) on rice production in two cultivars, Nipponbare and Koshihikari were evaluated in a long-term fertilization paddy field in Andosol Secondly, the effect of N levels on rice yield, NUE and grain quality in Nipponbare and Koshihikari was investigated in general paddy field Lastly, the pot experiment was conducted to investigate the effect of N levels on rice growth and NUE using different soil media which collected from long-term fertilization plots The results of study will contribute to improve the efficiency of fertilizer management on rice production in Andosol In long-term fertilization study, the application rate for each element in a standard (NPK) plot was 7.5 g m-2 Plots with no fertilizer, with a deficiency or double dose of N, P, and/or K, with Co, and with NPK plus calcium silicate or Co were investigated Six NUE parameters, N use efficiency for biomass (NUEb), N use efficiency for grain yield (NUEg), recovery efficiency of N (REN), agronomic efficiency of N (AEN), physiological efficiency of N (PEN), and partial factor productivity of N (PFPN), were measured Deficiency of P fertilizer had the most severe effect on rice production in Andosol The N2PK plot increased N uptake, grain yield, REN, AEN and PFPN, but usually decreased NUEb, NUEg and PEN compared to the NPK plot Taste value had a positive correlation with P level Increasing N level increased grain yield but decreased NUE parameters and taste value NP and NP2K plots negligibly affect grain yield, NUE parameters and taste value of Nipponbare; but the NP plot decreased grain yield, NUEg and PEN in Koshihikari The NPKSi plot increased grain yield and NUE parameters in both cultivars in 2018 Si had no effect on taste value of Nipponbare but i enhanced it of Koshihikari in 2018 The NPKCo plot did not lead to considerable improvement in rice yield and taste value while reduced NUE parameters Four N levels (0, 7, 8.5 and 10 g m-2 in 2018 and 0, 4, and 10 g m-2 in 2019) were used to assess the effect of N on rice production in Nipponbare and Koshihikari in general paddy field N fertilization increased dry weight, N uptake and grain yield compared to control (0 g m-2) Low N input condition (4 g m-2) decreased sink capacity compared to other N rates due to decrease in spikelet number However, dry weight and grain yield under N applied plots in both years were not significantly different among the N levels NUEb, NUEg, AEN and PFPN in 2018; and NUEb and PFPN in 2019 decreased significantly with increasing N level Taste value of Koshihikari correlated negatively to N level Thus, high N application was not beneficial for NUE and taste value while grain yield increase was not commensurate with increasing N level Koshihikari was cultivated with three N applied levels (0.3, 0.5 and 0.7 g pot-1) using five soil media collected from Zero (S ), PK (S PK ), NK (S NK ), NP (S NP ) and NPK (S NPK ) plots of long-term fertilization study Total N content in S and S NK were lower than those in S PK , S NP and S NPK N applied level had positive correlation with panicle number, whole grain number, dry weight and N uptake in all soil media Dry weight and N uptake in panicle and brown rice in S and S NK was significantly lower than those in S PK , S NP and S NPK, especially at low N applied level There was negative correlation between N applied level and NUEb in S and PFPN in S , S PK , S NP and S NPK N use efficiency for grain weight was not affected by N applied level Higher N uptake but lower NUEb in S NP and S NPK than in S , S PK and S NK under all N applied levels suggested that applying N fertilizer in high N content soils led to luxury N absorption N applied level did not affect whole grain percentage in S PK , S NP and S NPK but increased significantly this value in S and S NK Protein content was increased by N applied level in S and S PK The results showed that rice growth on nonfertilization soil and non-P fertilization soil was much dependent on N fertilizer Effect of N applied level on rice growth in non-N fertilization soil and non-K fertilization soil was similar to that in balance-fertilization soil In conclusion, P fertilizer has the most important role in rice production in Andosol paddy field N fertilizer is essential for rice growth and yield, but high N level adversely affects NUE and taste value To maintain grain yield and improve NUE and grain quality, we can reduce N application rate in combination with adequate P application K fertilizer may not be required for Nipponbare but should be applied to Koshihikari to maintain grain yield and NUE Si fertilizer could improve grain ii yield, NUE and taste value while combination Co with NPK improved negligibly rice growth and yield iii Contents Abstract i Contents iv List of abbreviations vi Chapter General introduction 1.1 Rice production and nitrogen, phosphate and potassium consumption for agriculture in the world 1.2 Nitrogen cycling in rice paddy soil and the effect of overuse nitrogen fertilizer 1.3 Nitrogen use efficiency - components and influencing factors 1.4 Rice grain quality 1.5 Long-term fertilization study in Tsukuba-Plant Innovation Research Center, University of Tsukuba, Japan and objectives of the research 12 Chapter Nutrient elements effects on rice production under long-term experiment 17 Abstract 17 2.1 Introduction 18 2.2 Materials and Methods 19 2.3 Results 23 2.4 Discussion 34 2.5 Conclusion 40 Chapter Nitrogen effects on rice production in general paddy field 73 Abstract 73 3.1 Introduction 74 3.2 Materials and Methods 75 3.3 Results 77 3.4 Discussion 81 3.5 Conclusion 85 Chapter Nitrogen effects on rice production under different soil media collected from long-term fertilization plots 114 Abstract 114 4.1 Introduction 115 4.2 Materials and Methods 116 iv 4.3 Results 118 4.4 Discussion 123 4.5 Conclusion 126 Chapter General conclusion 147 5.1 The role of nitrogen fertilization on rice production in Andosol 147 5.2 The role of phosphorus, potassium, calcium silicate and compost on rice production in Andosol 149 5.3 Prospects of dissertation 151 Acknowledgments 152 References 153 v List of abbreviations AC : Amylose content AEN : Agronomic efficiency of nitrogen ANOVA : Analysis of variance BRR : Brown rice rate Co : Compost CR : Contribution ratio DAT : Days after transplanting DBH : Days before heading HI : Harvest index K : Potassium KH : Koshihikari MRR : Milled rice rate LWR : Length/width ratio N : Nitrogen NB : Nipponbare NHI : Nitrogen harvest index NUE : Nitrogen use efficiency NUEb : Nitrogen use efficiency for biomass NUEg : Nitrogen use efficiency for grain yield P : Phosphorus PC : Protein content PEN : Physiological efficiency of nitrogen PFPN : Partial factor productivity of nitrogen REN : Recovery efficiency of nitrogen Si : Silicon SE : Standard error vi Chapter General introduction 1.1 Rice production and nitrogen, phosphate and potassium consumption for agriculture in the world Rice (Oryza sativa L.) is the most important staple food in the world, feeding more than 50 % of the world’s population (Gyaneshwar et al., 2001), and provides up to 76 % of the caloric intake for the population in South East Asia (Fitzgerald et al., 2009) The average rice harvested area increased from 121 million in 1961 - 1965 to 165 million in 2016 - 2018 (Figure 1-1) The expansion in harvested area was mainly due to an increase in cropping intensification In tropical climate countries such as Indonesia, Philippines, Vietnam, India, Bangladesh or southern China, rice is often cultivated in two or three growing seasons on the same land in a year (Nguyen and Ferrero, 2006) The average world rice production increased from 241 million tons in 1961 - 1965 to 768 million tons in 2016 2018 (Figure 1-1) because of the increment in grain yield as the result of genetic improvement and improved crop management (Horie et al., 2005) However, since 2000, the world rice production has been less than the world rice consumption (Nguyen and Ferrero, 2006) Based on formula described by Duwayri et al (2000), we calculated and found that the increase in the rate of rice yield decreased gradually from 3.0 % in 1981 - 1985 to 1.8 % in 1986 - 1990 and less than % in recent years (Figure 1-2) The increment of rice yield has hardly been observed across Asia in the past 10 years (Xue et al., 2013) Meanwhile, the global human population is projected to reach 8.9 billion by 2050 has posing a pressing challenge in modern agriculture (Pretty, 2008) Fageria (2007) estimated that rice production needs to increase to approximately 60 % more than current levels by 2025, corresponding to annual yield increases of at least 1.2 % (Normile, 2008), to meet the food demands of the growing world population Increasing fertilizer nutrient input has contributed considerably to improve crop yields globally (Xue et al., 2013) The amount of nitrogen (N), phosphate (P O ) and potassium (K O) fertilizers use for worldwide agricultural production has been increased gradually (Figure 1-3) In the past 15 years from 2002 to 2017, the N, P O and K O fertilizers consumption increased from 83.4 to 109.1 million tons, 34.6 to 45.5 million tons and 23.3 to 37.6 million tons, respectively The increment of global fertilizer consumption is the result of both cropland expansion and increase fertilizer application rate per unit cropland area (Lu and Tian, 2017) Although the increase rate in K O fertilizer (61 %) was higher than that in N and P O fertilizers (31 % for both), the global N consumption was much higher than P O and K O consumptions (Figure 1-3) Total N fertilizer application to cereals account for 55 % of total N fertilizer utilization, also higher than P O and K O fertilizer uses (49 % and 37 %, respectively) The three major cereals, wheat, rice and maize, accounted each for 15 to 18 % of the total N consumption for cereals (Heffer and Prud'homme, 2016) 1.2 Nitrogen cycling in rice paddy soil and the effect of overuse nitrogen fertilizer 1.2.1 Nitrogen cycling and nitrogen lose pathways in rice paddy soil In rice paddy soils, both biotic and abiotic N transforming reactions, including ammonification, immobilization, nitrification, denitrification, dissimilatory nitrate reduction to ammonium (DNRA), anaerobic ammonium oxidation (anammox) and nitrogen fixation, can appear (Figure 1-4) Organic N is converted to ammonium (NH +) through a biological process termed as ammonification or N mineralization The ammonification rate is generally slower in paddy field than in upland field due to the O depletion (Reddy and Patrick, 1984) However, the deficiency of O will restrict the immobilization wherein inorganic N convert to organic N through microbial assimilation of NH +, lead to further NH + accumulation in soil (Ishii et al., 2011) The balance between ammonification and immobilization is controlled primarily by organic matter quality, especially C-N ratio The microbes easily obtain N in organic matter with low C-N ratio, as the result of mineralization dominates over immobilization lead to plant-available N increases in soil In addition, these processes are influenced by soil properties such as pH, temperature and moisture content (Ranatunga et al., 2018) In thin surface oxidized layer, ammonium (NH +) released from fertilizer and mineralized from organic matter is oxidized to nitrate (NO -) via nitrite (NO -) This process is called 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