Stability and applicability of the leaf value model for variable nitrogen application based on SPAD value in rice

PLoS One. 2020 Jun 4;15(6):e0233735. doi: 10.1371/journal.pone.0233735. eCollection 2020.

Abstract

Many fertilization models have been created to scientifically determine the amount of fertilization. With the same purpose, we constructed a nitrogen (N) application model, the leaf value model, which can make N fertilizer decisions in a timely, fast and nondestructive manner during rice planting. However, only one area (A1, Jiuzhou Town, Xixiu District, Guizhou Province) and one cultivar (Qyou6) were involved in the construction of the leaf value model. Its stability and applicability could not be well evaluated. Thus, we chose another area (A2, Jiuzhou Town, Huangping County, Guizhou Province) in Guizhou Province and carried out the experiment by using four cultivars (Nie5you5399, Qyou6, Yixiangyou2115 and Zhongzheyou8) for the leaf value model construction. Compared with the average value of apparent total N uptake (Nz) obtained in 2 years in the A1 area, that in the Qyou6 leaf value model in the A2 area increased by 12%, reaching 635.72 kg ha-1, whereas the corresponding target yield changed slightly, reaching 10,999.90 kg ha-1. Simultaneously, the linear relationship between several good SPAD value-derived indexes (Ys) and apparent N supply of the field (Nx) was still significant or extremely significant in the Qyou6 leaf value model. Compared with the A1 area, it slightly differed, and the R2 of SPADL1 was higher than that of SPADL3×L4/mean. In the leaf value model of the other three cultivars, the relationship between yield and Nx and that between Ys and Nx were significant or extremely significant. The Nz of Yixiangyou2115 and Zhongzheyou8 (618.33 and 617.76 kg ha-1) were close to that of Qyou6 and the corresponding target yields were 10313.36 and 10301.99 kg ha-1, respectively. The Nz and target yield of Nie5you5399 were lowest at 546.63 and 10680.24 kg ha-1, respectively. In general, this study showed that relationships used in the construction of leaf value model had certain stability and applicability to difference areas and cultivars. The leaf value model can be considered in N fertilizer decision-making of rice planting management.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chlorophyll / analysis
  • Crop Production / methods
  • Fertilizers*
  • Models, Biological*
  • Nitrogen / administration & dosage*
  • Oryza / anatomy & histology
  • Oryza / chemistry
  • Oryza / physiology*
  • Plant Leaves / chemistry
  • Plant Leaves / physiology*
  • Soil / chemistry

Substances

  • Fertilizers
  • Soil
  • Chlorophyll
  • Nitrogen

Grants and funding

This work was supported by the National Natural Science Foundation of China (31360311, 31160263), the Subproject of Special fund project for Scientific Research of Public Welfare Industry (Agriculture) (201503118-03), the Scientific and Technological Innovative Talents Team for Cultivation and Eco-Physiology Research of Featured Grain and Oil Crops in Guizhou Province (Grant no. Qiankehe Platform Talents [2019] 5613), the Talents Program of High Level and Innovative in Guizhou Province (Grant no. Qiankehe Platform Talents [2018]5632), the Construction Program of Biology First-class Discipline in Guizhou Province (GNYL [2017]009) and the Agricultural Scientific and Technological Project in Guizhou Province (Qiankehe NY[2013]3005).