Growth response of six weed species and spring barley (Hordeum vulgare) to increasing levels of nitrogen and phosphorus

Abstract

A glasshouse experiment was carried out to investigate the influence of increasing levels of nitrogen and phosphorus on the growth of six common weed species growing alone or in competition with spring barley (Hordeum vulgare). Capsella bursa-pastoris, Chenopodium album, Papaver rhoeas, Sinapis arvensis, Spergula arvensis, Viola arvensis and spring barley were grown in pots with different levels of nitrogen (0, 30, 60, 90, 120 and 150 kg N ha )1 ) or phosphorus (0, 10, 20, 30, 40 and 60 kg P ha )1 ). The aboveground parts of the plants were harvested after 7 weeks and the dry weight of shoots, percentage N and P content of the shoot and uptake of N and P were determined. A linear or a polynomial model was used to describe the data. Growing alone, Spergula arvensis was the only weed species that increased its dry weight at the same rate as barley. Weed species with low dry weight increase had larger increases in percentage N or P content than barley, indicating a luxury accumulation of nutrients. The uptake of N and P per pot did not differ much between weeds and barley. V. arvensis and P. rhoeas accumulated least nutrients (per cent of dry matter) and Spergula arvensis accumulated most. Weeds grew poorly in competition with barley. The percentage N and P content in barley did not change when they grew in competition with weeds.a ¼ Slope of the line or second constant in the polynomial model (Y ¼ l + aX + bX 2 ). àb ¼ constant in the polynomial model (Y ¼ l + aX + bX 2 ).Weed growth response to increasing N and P levels 505

Long-Term Management Affects the Community Composition of Arable Soil Seedbanks

“…In this situation most weeds are at disadvantage for light and nutrient uptake, which may negatively affect seed production and, consequently, the replenishment of their seeds in the soil seedbank (Andreasen et al 2006;Moonen and Bàrberi 2004;Pyšek and Lepš 1991). This, together with the herbicide use, would partly explain why farming systems with higher nitrogen availability (CONFYM and CONMIN) had lower weed seed density in the soil seedbank.…”

Growth and mineral nutrition of Solanum americanum

“…Information on the nutritional requirements of weeds is important to weed science, since nutrient competition is one of the main ecological factors that affect negatively crop productivity (Andreasen et al, 2006;Olykan et al, 2008). Due to this fact, important studies have already been conducted for Senna obtusifolia (Erasmo et al, 2000), Urena lobata (Souza Filho et al, 2000), Cardiospermum halicacabum (Brighenti et al, 2003), Richardia brasiliensis competing with Glycine max (Pedrinho Júnior et al, 2004), Quercus petraea, Fagus sylvatica, Acer pseudoplatanus (Kazda et al 2004), Brachiaria decumbens (Bianco et al, 2005), Euphorbia heterophylla competing with G. max (Bianco et al, 2007), Brachiaria plantaginea competing with Zea mays , Ipomoea nil (Duarte et al, 2008) and Ipomoea quamoclit (Carvalho et al, 2009).…”

Effects of different densities of wild oat (Avena fatua L.) and nitrogen rates on oilseed rape (Brassica napus L.) yield

“…Crop yield in weedy, fertilized plots are usually equal to those in weeded, un-fertilized plots (Zimdahl 2004). It has been shown that increased nitrogen could enhance the competitiveness of weeds more than crops, and crop yield remained either unchanged or decreased in some cases (Carlson and Hill 1985, Ampong-Nyarko and de Datta 1993, Santos et al 1998, Dhima and Eleftherohorinos 2001, Andreasen et al 2006. Studying competition between wild mustard (Sinapis arvense) and oilseed rape under different rates of nitrogen fertilizer, Naderi and Ghadiri (2011) reported that increase in nitrogen levels only increased the competitiveness of wild mustard over oilseed rape.…”