Intercepted solar radiation by maize crops subjected to different tillage systems and water availability levels

Abstract

-The objective of this work was to evaluate changes in the photosynthetic photon flux density (PPFD) interception efficiency and PPFD extinction coefficient for maize crop subjected to different soil tillage systems and water availability levels. Crops were subjected to no-tillage and conventional tillage systems combined with full irrigation and non-irrigation treatments. Continuous measurements of transmitted PPFD on the soil surface and incoming PPFD over the canopy were taken throughout the crop cycle. Leaf area index and soil water potential were also measured during the whole period. Considering a mean value over the maize cycle, intercepted PPFD was higher in the conventional tillage than in the no-tillage system. During the initial stages of plants, intercepted PPFD in the conventional tillage was double the PPFD interception in the no-tillage treatment. However, those differences were reduced up to the maximum leaf area index, close to tasseling stage. The lowest interception of PPFD occurred in the conventional tillage during the reproductive period, as leaf senescence progressed. Over the entire crop cycle, the interception of PPFD by the non-irrigated plants was about 20% lower than by the irrigated plants. The no-tillage system reduced the extinction coefficient for PPFD, which may have allowed a higher penetration of solar radiation into the canopy.Index terms: Zea mays, leaf area, no-tillage, photosynthetic photon flux density, water deficit. Radiação solar interceptada pela cultura do milho sob diferentes níveis de preparo do solo e disponibilidade hídricaResumo -O objetivo deste trabalho foi avaliar a eficiência da interceptação da radiação fotossinteticamente ativa (RFA) e o coeficiente de extinção da cultura do milho em diferentes sistemas de preparo do solo e níveis de disponibilidade hídrica. O milho foi cultivado em sistemas de plantio direto e preparo convencional combinados a tratamentos de irrigação completa e sem irrigação. Medições contínuas de RFA transmitida à superfície do solo e RFA incidente sobre o dossel foram tomadas ao longo do ciclo da cultura. O índice de área foliar (IAF) e o potencial da água no solo também foram medidos em todo o período. Na média de todo o ciclo da cultura, a RFA interceptada foi maior em preparo convencional do que em plantio direto. Nos estádios iniciais das plantas, a RFA interceptada em preparo convencional foi o dobro daquela em plantio direto. Porém, essas diferenças reduziram-se até o máximo IAF, próximo ao pendoamento. A menor interceptação de RFA pela cultura ocorreu em preparo convencional durante o período reprodutivo, à medida que a senescência foliar progrediu. No ciclo todo, a interceptação de RFA pela cultura não irrigada foi 20% menor que na irrigada. O sistema plantio direto reduziu o coeficiente de extinção de RFA pelo milho, e proporcionou maior penetração de radiação solar no dossel.Termos para indexação: Zea mays, área foliar, plantio direto, radiação fotossinteticamente ativa, deficit hídrico.

Effects of rainwater harvesting on herbage diversity and productivity in degraded Aravalli hills in western India

“…This suggests that a population with unevenly distributed species has capacity of higher interception producing higher biomass (r = 0.262, p < 0.05 at LSP). PAR interception by the maize plants cultivated under conventional tillage was 30% higher than that in the maize plants cultivated under no-tillage system (Bergamaschi et al 2010).…”

Thermo-physical-hydraulic variables in a no-tillage system related to wheeled traffic and furrow-opening mechanisms

“…The temperature variations observed in the more superficial soil layers are mainly affected by soil texture and structure, besides being directly related to ionic exchanges between the root system and the soil; however, they are also influenced by the soil management system (Bergamaschi et al, 2010;Veiga et al, 2010;Montanari et al, 2012). Under the no-tillage system, for example, plant cover has an important role in the dynamics of soil temperature, and the main problems related to soil temperature and nutrients refer to their solubility (Grant et al, 2001).…”

Corn agronomic traits and recovery of nitrogen from fertilizer during crop season and off-season

“…The fall-winter season was relatively dry (664 mm), while the springsummer was rainy (1,329 mm). Furthermore, worse agronomic traits were observed in the fall-winter, mostly due to the lower temperature in this period, which reduces plant growth and, consequently, the photosynthesis efficiency (Dohleman & Long, 2009;Bergamaschi et al, 2010;Chen et al, 2013).…”