Open AccessStability and applicability of the leaf value model for variable nitrogen application based on SPAD value in rice
Author(s) -
Jie Li,
Feng Yue,
Xiaoke Wang,
Jinfeng Peng,
Yang DingHua,
Gang Xu,
Qiangxin Luo,
Lingli Wang,
Da Ou,
Wei Su
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0233735
Subject(s) - cultivar , sowing , yield (engineering) , human fertilization , mathematics , fertilizer , value (mathematics) , nitrogen , agronomy , nitrogen fertilizer , horticulture , environmental science , statistics , biology , chemistry , physics , organic chemistry , thermodynamics
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 (A 1 , 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 (A 2 , 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 (N z ) 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 (Y s ) and apparent N supply of the field (N x ) was still significant or extremely significant in the Qyou6 leaf value model. Compared with the A 1 area, it slightly differed, and the R 2 of SPAD L1 was higher than that of SPAD L3×L4/mean . In the leaf value model of the other three cultivars, the relationship between yield and N x and that between Y s and N x were significant or extremely significant. The N z 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 N z 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.