Tolerance to low phosphorus was enhanced by an alternate wetting and drying regime in rice

Rice production in Tanzania, with 67% of its territory considered semi-dry and having average annual rainfall of 300 mm, must be increased to feed an ever-growing population. Water for irrigation and low soil fertility are among the main challenges. One way to decrease water consumption in paddy fields is to change the irrigation regime for rice production, replacing continuous flooding with alternate wetting and drying. In order to assess the impact of different irrigation regimes and nitrogen fertilizer applications on growth, yield, and water productivity of rice, a greenhouse pot experiment with soil from lowland rice ecology was conducted at Sokoine University of Agriculture, Tanzania during the 2019 cropping season. The experiment was split-plot based on randomized complete block design with 12 treatments and 3 replications. Water regimes were the main factors comparing continuous flooding (CF) and alternate wetting and drying (AWD) with nitrogen fertilizer levels as the subfactor, comparing absolute control (no fertilizer) with 0 (P and K fertilizers), 60, 90, 120, and 150 kg Nha−1. Alternate wetting and drying (AWD) significantly improved water productivity by 8.3% over CF (p < 0.05). Water productivity (WP) ranged from 0.6 to 1.5 kg of rice per m3 of water. Average water use ranged from 36 to 82 L per season, and water saving was up to 34.3%. Alternate wetting and drying significantly improved yields (p < 0.05) by 13.3%, and the yield ranged from 21.8 to 118.2 g pot−1. The combination of AWD water management and 60 kg N ha−1 nitrogen fertilization application was found to be the optimal management, however there was no significant difference between 60 and 90 kg N ha−1, in which case 60 kg N ha−1 is recommended because it lowers costs and raises net income. Nitrogen levels significantly affected water productivity, water use, and number of irrigations. Nitrogen levels had significant effect (p < 0.05) on plant height, number of tillers, flag leaf area, chlorophyll content, total tillers, number of productive tillers, panicle weight, panicle length, 1000-grain weight, straw yield, grain yield, and grain harvest index. The results showed that less water can be used to produce more crops under alternative wetting and drying irrigation practices. The results are important for water-scarce areas, providing useful information to policy makers, farmers, agricultural departments, and water management boards in devising future climate-smart adaptation and mitigation strategies.

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“…Rice is also the largest consumer of water among all crops [7,8]. The water productivity of rice is lower than those of other crops [9].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Growth, Yield, and Water Productivity of Paddy Rice with Water-Saving Irrigation and Optimization of Nitrogen Fertilization

et al. 2021

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“…Apart from the direct product of photosynthesis in the crops after anthesis, the NSC reserves stored in stems and sheaths pre‐anthesis are the important sources for grain yield (Austin et al, 1977; Duan et al, 2018). Many studies have shown that the transportation of carbon assimilates stored in the temporary source tissues to the grains can be intensified in cereal crops when facing adversary conditions like soil drying (Deng et al, 2021; Wu et al, 2019; Xu et al, 2016). In a maize experiment with different irrigation amounts, the most photosynthate was transported from leaves and stalks to kernels in the minimum irrigation regime, and the lowest transfer occurred in the maximum irrigation regime (Wang et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

Moderate soil drying improves physiological performances and kernel yield of maize

Yuan

Zhou

et al. 2022

Food and Energy Security

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Water resources shortage and drought are prominent problems in the world. Losses of the world economy and society caused by drought amount to the sum of losses caused by other natural disasters according to statistics (Musolino et al., 2018). China is one of the poorest water resources countries worldwide, and has the largest irrigated cropland and consumes 13.4%-19.3% of the world's total irrigation water consumption (Yin et al., 2020). Moreover,

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“…The dried samples of rice plant organs were used to determine both P and nonstructural carbohydrates (NSC) content. The measurement of P accumulation was using the method described by Deng et al [21]. The NSC content in the stem (including culms and sheaths) at the heading time and maturity was determined using the method of anthrone proposed by Yoshida et al [35].…”

Section: Phosphorus Content and Non-structural Carbohydrate Remobiliz...mentioning

confidence: 99%

“…However, excessive P input is a prominent problem, leading to a low PUE and environmental pollution. In response to this challenge, agronomists consider the adoption of P-efficient indica rice varieties as an important strategy to reduce P input, improve grain yield, and promote environmental sustainability [21,22]. Given that root and shoot traits directly or indirectly drive the release of soil available P content, it is therefore that substantial attention should be directed toward unraveling the relationship between PUE and plant traits in indica rice, particularly under the limited P conditions.…”

Section: Introductionmentioning

confidence: 99%

“…It is suggested that rice varieties that exhibit better yield performance under low P condition, i.e., strong tolerance to low P, could serve as a significant evaluation indicator for screening P-efficient varieties. Although some plant traits related to P-efficient rice varieties have been elucidated in previous studies, the coverage is not yet comprehensive, especially concerning plant hormones [21,28]. For example, there are reports showing that elevated auxin content in roots under low P conditions can uptake more P in soil by shaping the root morphology [29,30].…”

Section: Introductionmentioning

confidence: 99%

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Agronomic and Physiological Performance of the Indica Rice Varieties Differing in Tolerance to Low Phosphorus

Sun,

Qiao,

et al. 2023

Agronomy

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Phosphorus (P) deficiency and low P use efficiency (PUE) are limiting factors in rice (Oryza sativa L.) production. Understanding the agronomic and physiological traits of P-tolerant rice varieties is crucial for improving PUE. However, the agronomic and physiological traits of rice varieties differing in tolerance to low P have not been fully studied or comprehensively explored. Two varieties with strong tolerance to low P (STVs, low P tolerance index > 0.9) and two with weak tolerance to Low P (WTVs, low P tolerance index < 0.5) were grown hydroponically with normal P level (NP, 8.02 mg L−1) and low P level (LP, 0.401 mg L−1) in year 2020 and 2021. Results showed that, compared with NP, the LP significantly decreased grain yield, but enhanced P translocation efficiency (PTE), internal P use efficiency (IPE), and P harvest index (PHI) in all the varieties. The STVs showed better performance than the WTVs. Specifically, the STVs exhibited a 131.33% higher grain yield, 15.95% higher PTE, 41.6% higher IPE, and 8.84% higher PHI compared to the WTVs. The STVs also exhibited superior shoot traits, including increased productive tillers, leaf area index (LAI), leaf photosynthetic rate, shoot biomass, contents of indole-3-acetic acid (IAA) and zeatin (Z) and zeatin riboside (ZR) in leaves, non-structural carbohydrates (NSC) remobilization during grain filling, and content of NSC per spikelet, when compared to the WTVs under the LP treatment. Additionally, the STVs demonstrated better root traits, such as higher root biomass, root oxidative activity (ROA), root acid phosphatase (RAP) activity, and greater root IAA and Z + ZR contents. These shoot and root traits exhibited highly positive correlations with grain yield, PTE, and IPE. In conclusion, the STVs maintain higher grain yield and PUE under the LP treatment, due mainly to their improved root and shoot agronomic and physiological traits, which provide valuable references for selecting for P-efficient rice varieties.

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Tolerance to low phosphorus was enhanced by an alternate wetting and drying regime in rice

Cited by 6 publications

References 70 publications

Evaluation of Growth, Yield, and Water Productivity of Paddy Rice with Water-Saving Irrigation and Optimization of Nitrogen Fertilization

Evaluation of Growth, Yield, and Water Productivity of Paddy Rice with Water-Saving Irrigation and Optimization of Nitrogen Fertilization

Moderate soil drying improves physiological performances and kernel yield of maize

Agronomic and Physiological Performance of the Indica Rice Varieties Differing in Tolerance to Low Phosphorus

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