Direct and Indirect Effects of Planting Density, Nitrogenous Fertilizer and Host Plant Resistance on Rice Herbivores and Their Natural Enemies

Finbarr G. Horgan (), Eduardo Crisol-Martínez, Alexander M. Stuart, James M. Villegas, Ainara Peñalver-Cruz, Enrique A. Mundaca, Marivic O. Perez, Carmencita C. Bernal, Maria Liberty P. Almazan and Angelee F. Ramal
Additional contact information
Finbarr G. Horgan: EcoLaVerna Integral Restoration Ecology, Bridestown, Kildinan, T56 P499 County Cork, Ireland
Eduardo Crisol-Martínez: EcoLaVerna Integral Restoration Ecology, Bridestown, Kildinan, T56 P499 County Cork, Ireland
Alexander M. Stuart: International Rice Research Institute, Makati 1226, Metro Manila, Philippines
James M. Villegas: International Rice Research Institute, Makati 1226, Metro Manila, Philippines
Ainara Peñalver-Cruz: International Rice Research Institute, Makati 1226, Metro Manila, Philippines
Enrique A. Mundaca: Escuela de Agronomía, Facultad de Ciencias Agrarias y Forestales, Universidad Católica del Maule, Casilla 7-D, Curicó 3349001, Chile
Marivic O. Perez: International Rice Research Institute, Makati 1226, Metro Manila, Philippines
Carmencita C. Bernal: International Rice Research Institute, Makati 1226, Metro Manila, Philippines
Maria Liberty P. Almazan: International Rice Research Institute, Makati 1226, Metro Manila, Philippines
Angelee F. Ramal: School of Environmental Science and Management, University of the Philippines, Los Baños 4030, Laguna, Philippines

Agriculture, 2022, vol. 12, issue 12, 1-27

Abstract: In rice ecosystems, seeding densities can be adjusted to compensate for lower nitrogen levels that reduce GHG emissions, or to increase farm profitability. However, density-induced changes to plant anatomy could affect herbivore-rice interactions, and alter arthropod community dynamics. We conducted an experiment that varied transplanting density (low or high), nitrogenous fertilizer (0, 60 or 150 kg added ha −1 ) and rice variety (resistant or susceptible to phloem-feeding insects) over two rice-growing seasons. Yields per plot increased with added nitrogen, but were not affected by variety or transplanting density. Planthopper and leafhopper densities were lower on resistant rice and in high-density field plots. Nitrogen was associated with higher densities of planthoppers, but lower densities of leafhoppers per plot. High planting densities and high nitrogen also increased rodent damage. The structure of arthropod herbivore communities was largely determined by season and transplanting density. Furthermore, two abundant planthoppers ( Sogatella furcifera (Horváth) and Nilaparvata lugens (Stål)) segregated to low and high-density plots, respectively. The structure of decomposer communities was determined by season and fertilizer regime; total decomposer abundance increased in high-nitrogen plots during the dry season. Predator community structure was determined by season and total prey abundance (including decomposers) with several spider species dominating in plots with high prey abundance during the wet season. Our results indicate how rice plasticity and arthropod biodiversity promote stability and resilience in rice ecosystems. We recommend that conservation biological control, which includes a reduction or elimination of insecticides, could be promoted to attain sustainable rice production systems.

Keywords: Bph3; Bph32; density dependence; herbivory tolerance; parasitoids; pesticides; regulatory ecosystem services; rice yields; tillering; tropical rice (search for similar items in EconPapers)
JEL-codes: Q1 Q10 Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2077-0472/12/12/2053/pdf (application/pdf)
https://www.mdpi.com/2077-0472/12/12/2053/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jagris:v:12:y:2022:i:12:p:2053-:d:988495

Access Statistics for this article

Agriculture is currently edited by Ms. Leda Xuan

More articles in Agriculture from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().