Nitrogen Effects on Yield, Quality and Physiological Characteristics of Giant Rice

Abstract

In China, the quantity of nitrogen fertilizer applied is large, but as a consequence of a high level of loss, its utilization rate is low. Compared to common rice, the new giant rice has interesting characteristics, namely high biological yield and good efficient use of fertilizer. However, it becomes urgent to further consider the appropriate rate of nitrogen fertilizer to be applied. The giant rice varieties Feng5 and Feng6 were set up in a pot experiment and a field experiment under five doses of nitrogen fertilizers, namely, 0 kg·ha−1 (CK), 75 kg·ha−1 (T1), 150 kg·ha−1 (T2), 225 kg·ha−1 (T3) and 300 kg·ha−1 (T4). Parameters such as leaf area index (LAI), lodging index (LI), nitrogen utilization rate, photosynthesis rate and grain yield were measured. The results showed that with the increase of nitrogen dose in a certain range, LAI, plant height, the number of tillers, net photosynthetic rate (NPn), the transpiration rate (Tr), and the grain yield increased while the lodging index (LI), the nitrogen agronomic utilization rate (AE) and nitrogen partial productivity (PFPN) decreased. Additionally, with the increase of nitrogen application, the grain yield index (HI) and nitrogen contribution rate (FCRN) of rice presented a parabolic trend.

Yield, Grain Quality, and Starch Physicochemical Properties of 2 Elite Thai Rice Cultivars Grown under Varying Production Systems and Soil Characteristics

“…The deficiency of micronutrients (e.g., iron (Fe)) also affected numerous metabolic processes such as DNA synthesis, respiration, and photosynthesis [34,35]. As a result, the rice plant exposed to nutrient imbalance typically shows characteristic symptoms, such as poor root formation, thinner stems, folded leaves, pale green and dark brown necrotic spots, and yellow, burnt-orange and dying leaves, which ultimately lead to the retardation of normal growth and the decreases of tillering, panicle number, and yield ability of the rice [32][33][34][35][36][37]. For instance, nitrogen and phosphorous deficiency in soil can cause the decreases of rice photosynthesis, growth, development, yield, and grain storage product compositions (e.g., amylose and protein contents) [30,[37][38][39].…”

“…As a result, the rice plant exposed to nutrient imbalance typically shows characteristic symptoms, such as poor root formation, thinner stems, folded leaves, pale green and dark brown necrotic spots, and yellow, burnt-orange and dying leaves, which ultimately lead to the retardation of normal growth and the decreases of tillering, panicle number, and yield ability of the rice [32][33][34][35][36][37]. For instance, nitrogen and phosphorous deficiency in soil can cause the decreases of rice photosynthesis, growth, development, yield, and grain storage product compositions (e.g., amylose and protein contents) [30,[37][38][39]. Furthermore, soil potassium deficiency is a main cause of declines in translocation of photosynthetic products and other metabolites from leaves to pollen grains at the reproductive stage, resulting in spikelet sterility, unfilled grain percentage per panicle, reduced grain size and grain weight, and yield loss in rice [31,40].…”

Novel QTL Associated with Shoot Branching Identified in Doubled Haploid Rice (Oryza sativa L.) under Low Nitrogen Cultivation

“…It is said that tiller number determines the number panicles per plant [ 39 , 64 , 65 ], which happens to be an important yield component of rice. The number of tillers is influenced by environmental factors [ 66 ], agricultural practices, including nitrogen fertilization [ 67 , 68 , 69 , 70 , 71 , 72 ], or genetic factors [ 65 , 73 , 74 , 75 , 76 , 77 ]. It is also expected that an increase or decrease in tiller number per plant could cause significant changes in the shoot biomass.…”

Response of root development and nutrient uptake of two chinese cultivars of hybrid rice to nitrogen and phosphorus fertilization in Sichuan Province, China

“…It showed a positive correlation of R=1 in the N 120 treatment. Similarly, many studies have shown that rice yield increases with the increase of nitrogen application within a certain range, but the yield decreases when the nitrogen application is too high [39,40].…”

“…Plant samples of all treatments were collected at four time points (10,25,40,55 days after treatment) in 2019. Fresh samples were used for morphological measurements and gene expression studies.…”