The aim of this papers is to discuss the expected effect of increasing phosphorus accumulation in cultivated soils. The global consumption of phosphorus fertilisers since 1954 exceeded 1 billion tons of P2O5, and about a half of this amount was used in European countries. More than 95% of mined phosphate rocks are provided to food production. That resulted that the total phosphorus content in agricultural used soils was doubled or tripled in European countries up to now. A further increase of phosphorus accumulation in the- cultivated soils would conduct to eutro- phication of water and terrestrial ecosystems. The euthrophication of surface water is rather good known phenomena, but the euthrophication of terrestrial ecosystem need broader identification. Main sources of phosphorus in environment is food production and consumption. In agriculture, a renewed attentions is required to ensure that phosphorus in modern farming systems is managed in a manner which is sustainable from the point of view of both agriculture and environment. The mitigation of eutrophication originated from phosphorus accumulation in agricultural soils could be achieved only on scientific basis followed with country and regional abatement programs.
The research was intended to analyse the response of five papaya varieties to phosphorus fertilization in tidal swamp areas. The research was conducted at the Peatland Project (PLG) in Mentangai, Kapuas, Central Kalimantan, from August 2007 to April 2008. A split plot design was used. The main plot had the following P application: 100; 200; 300 g P/plant, and the subplot had the following varieties of papaya: Bt1; Bt2; Bt3; Bt4; Bt7. There were 3 replications and 10 plants per unit of treatment. The observed parameters were: (1) vegetative growth (plant height, stem diameter, internode number); (2) and fruit quality (fruit number, fruit weight, fruit length, fruit circumference, flesh thickness, and total soluble solid). The research result showed that four of five papaya varieties, namely Bt1, Bt2, Bt4, and Bt7 proved to have a higher growth and production response than Bt3. Therefore, the four varieties Bt1, Bt2, Bt4, and Bt7, show good prospects for development in the tidal swamp areas. P application affected significantly plant height only, but did not have an effect on other parameters of plant growth and fruiting. These findings could be used as a guide for choosing varieties suitable for cultivation in the tidal swamp areas.
Although diversity-ecosystem theory predicts that ecosystem functioning is strongly determined by species number, species traits play an important role in regulating ecosystem-level dynamics. We analyze responses of species attributes to diversity level and resource availability, and explore their consequences for ecosystem functioning and ultimately assess the contributions of five traits (vegetative plant height, clonal growth, root depth, cespitose habit and seed mass) to ecosystem functioning defined by spatial stability of community biomass. We found that functional traits disproportionately affected spatial stability. Relationships between species functional traits and spatial stability of community biomass indicated that diversity of vegetative plant height facilitated stability of a nitrogen fertilized undisturbed natural community (NAT), and that of a phosphorus fertilized forb, legume and bunchgrass community (FLB). The clonal growth form was also identified as a stabilizing trigger for a unfertilized undisturbed natural community (NAT), whereas diversity in root depth, cespitose habit and seed mass were related to destabilization of a nitrogen fertilized rhizomatous grass community (RRR). Studies quantifying interactions among plant traits, community structure and ecological functioning will contribute much more to understanding of the effects of the ecological behavior of specific traits on the ecosystem functioning.
The aim of the paper was to evaluate the efficiency of nitrogen from ammonium saltpeter as related to the formulation of phosphorus fertilizer under maize grain cropping. Maize was grown in monoculture throughout the consecutive years 2003-2007. A two factorial field experiment was established at a farm located in Nowa Wieś Królewska (52°26’ N; 17°57’ E) on a slightly acidic soil, moderately rich in phosphorus. Experimental factors were as follows: (i) chemical formulation of the fertilizer, (partially acidulated phosphate rock – PAPR, simple superphosphate – SSP and triple superphosphate – TSP), (ii) nitrogen rate: 80 and 140 kg N·ha⁻¹; a phosphorus unfertilized treatment was also considered. The type of phosphorus fertilizer did not differentiate nitrogen uptake, but the lack of phosphorus at the applied rate has induced a decrease in nitrogen accumulation in the aboveground biomass, on average by 8%. Phosphorus fertilization at the rate 26.4 kg P·ha⁻¹ was the main determinant of nitrogen uptake by the kernels. Nitrogen recovery (R) from the fertilizers as well as its agronomical (AE) and physiological (PE) efficiency were significantly lower in treatments where phosphorus was not applied. Furthermore, it was found a positive effect of sulphur from simple superphosphate on the AE after the application of 80 kg N·ha⁻¹. The R values did not depend on the chemical formulation of phosphorus in the fertilizer and amounted on average to 74 and 59% for the rates 80 and 140 kg N·ha⁻¹, respectively, whereas for the treatment without P, these values varied within the range 46-54%.
Optimal nutrition of cultivated plants at critical growth stages is of great importance for the achievement of full crop yield potential. The aim of this study was to assess the maize yield response and plant nutritional status at a critical stage of growth (BBCH 17) under the most favourable and reduced fertilization with phosphorus and potassium. It was assumed that the nutritional status of maize at BBCH 17 stage significantly influenced the plant growth and yielding. The hypothesis was tested in a one-factorial trial, carried out on the maize variety Veritis in 2007-2011, which was a part of a long-term study started in 2000 according to a randomized complete block design. The factor tested comprised different phosphorus and potassium doses applied at constant levels of nitrogen and magnesium fertilization. The yields of maize significantly differed between the treatments and in relation to the control. In each year, maize responded with a lower yield to the no-phosphorus treatment when compared to the no-potassium treatment. Irrespective of the fertilization variants, the content of the nutrients tested (except iron) was below the standard value. A significant relationship was shown between the nutritional status of maize at the stage of 7 leaves unfolded (BBCH 17) and grain yield. The coefficients of determination ranging from 59% to 94% showed that, irrespective of which treatment was applied, the mineral nutrient content in maize leaves at BBCH 17 stage had the strongest influence on the maize yield.
A plant growing experiment was conducted in 2002-2003 on the aubergine cultivars Epic F1 and Solara F1 grown in an unheated polyethylene tunnel greenhouse at the Experimental Station in Marcelin, the University of Life Sciences in Poznań. Seedlings were planted on May 15 on beds at a 0.5 × 0.5 m spacing, i.e. 4 plants m–2, into 6 dm3 cylinders filled with a mixture, limed to pHH2O = 6.5, of mineral soil (light loamy sand containing 12% clay fraction – deposited on medium-heavy loam) with highmoor peat from Lithuania (v : v = 4 : 1). Basic fertilization – pre-vegetation and top dressing with macronutrients, based on an analysis of the substrate using the universal method in 0.03 M CH3COOH, was determined to attain the assumed levels: L (N – 200, P – 175, K – 330 mg dm–3), S (N – 300, P – 265, K – 500 mg dm–3), H (N – 400, P – 350, K – 665 mg dm–), while maintaining the N : P : K ratio at 1 : 0.9 : 1.7. The aim of this study has been to determine the effect of a fertilization level and cultivar on the yield and biological value of fruits of aubergine grown on a mixture of mineral soil with highmoor peat (v : v – 4 : 1). The total yield, number of fruits and weight of individual fruits were determined. Significant effect was found for the fertilization level and cultivar on the total yield, mean number of fruits and weight of a single aubergine fruit. Fruits of cv. Epic F1 aubergine contained more vitamin C than fruits of cv. Solara F1. In both years, the solids content in fruits of the two aubergine cultivars ranged from 4.0 to 5.5 %. A higher mean dry matter content in aubergine fruits was recorded in cv. Solara F1.
Doświadczenie polowe przeprowadzono w latach 2001-2003 w Zakładzie Doświadczalno-Dydaktycznym w Swadzimiu koło Poznania. Jego celem było określenie wpływu sposobu nawożenia na gromadzenie suchej masy i zawartość składników mineralnych w początkowym okresie wzrostu oraz plonowanie kukurydzy. Stosowano dwa sposoby nawożenia: rzutowo na całą powierzchnię przed siewem nasion i rzędowo (startowo) jednocześnie z siewem nasion. Skuteczność sposobów nawożenia badano stosując nawóz fosforowy, fosforowo-azotowy i nawozy wieloskładnikowe. Nawożenie rzędowe powodowało wzrost suchej masy części nadziemnych młodych roślin kukurydzy oraz zwiększało w nich zawartość fosforu i azotu, a obniżało zawartość magnezu i wapnia. Nawóz wieloskładnikowy amofoska był jedynym nawozem, który zastosowany rzędowo nie stymulował wzrostu początkowego roślin. Rzędowa aplikacja nawozów zwiększała istotnie plon ziarna w porównaniu z nawożeniem rzutowym.
This paper presents results of research on the impact of two levels of Nitrogen (N) and Phosphorus (P) fertilization use on population, height of plants, and biomass yield of Virginia fanpetals cultivated on light sandy loam, during four consecutive years of research: 2004-07. Results indicate that stem density and height grew systematically during consecutive years of production. Nitrogen treatment did not influence density, but it increased height of plants. A larger quantity and height of stems was observed after using a higher dose of Phosphorus. Virginia fanpetal biomass yield was not affected by different amounts of Nitrogen applied, whereas more intensive Phosphorus treatment resulted in increased biomass yield. In the third and fourth years of production an average yield of dry matter of over 11 t·ha⁻¹ was obtained; energy productivity level was 219.5 GJ·ha⁻¹.