was low under both management systems: 12 <strong>and</strong> 15 kg grain kg/N, for intensive <strong>and</strong> traditional, respectively. Likewise, Agronomic Efficiency was extremely low (3 kg grain/kg N for both management systems). IPNI-29 44 IPNI Interpretive Summaries
<strong>Americas</strong> <strong>and</strong> <strong>Oceania</strong> <strong>Group</strong> Brazil: Dr. Luís Ignácio Prochnow Sustainable Production Systems under No-Till in the Cerrado of Brazil Project Leader: Eros A.B. Francisco, Research Foundation MT, Rondonopolis, MT. E-mail: erosfrancisco@fundacaomt.com.br Project Cooperators: Ciro Rosolem, rosolem@fca.unesp.br <strong>and</strong> Le<strong>and</strong>ro Zancanaro, le<strong>and</strong>rozancanaro@fundacaomt.com.br Continuous l<strong>and</strong> cultivation with mono-cropping systems tends to promote soil degradation <strong>and</strong> increase the incidence of crop diseases, pests, <strong>and</strong> weeds, which in turn reduce crop yield potential. A long-term research project was initiated to look into various aspects of sustainable agricultural systems. The project focuses on crop rotation <strong>and</strong> other alternatives to generating long-term profitability. Part of this project is dedicated to the study of soil fertility management under these sustainable agriculture systems. Two experiments, one aimed at the production of fiber <strong>and</strong> the other at grain production, each containing seven different cropping systems, were initiated in 2008. Results suggest that the production of dry matter of cover crops during the spring, before cotton, is sufficient for good soil protection <strong>and</strong> recycling of nutrients. Amounts of N, P, K, Ca, Mg, <strong>and</strong> S recycled by millet <strong>and</strong> Brachiaria grass were identical, while the amount of K recycled was higher for systems utilizing Brachiaria in the autumn <strong>and</strong> millet in the spring. The type of cover crop utilized during the spring did not influence cotton yield. The soil density was higher under no-tillage compared to annual soil tillage, but no fiber yield reduction occurred. For farming systems under no-tillage, soil density may be alleviated using Brachiaria grass for periods longer than 12 months, which may be an advantage for farming systems including pasture crops. The use of cover crops after soybean harvest is essential to sustain soil biological activity <strong>and</strong> nutrient cycling, <strong>and</strong> crotalaria showed higher levels of N cycled than Brachiaria <strong>and</strong> millet. Soil P levels were found to be lower in the farming systems with no use of cover crops after soybean, whereas the use of Brachiaria grass showed to increase P level in the soil. Soybean yields were affected when it followed corn intercropped with Brachiaria. This could be related to immobilization of N in corn <strong>and</strong> Brachiaria residues. The intensification of the farming system with soybean <strong>and</strong> corn (second crop) in sequence resulted in higher amounts of nutrient export, which should be taken into consideration when planning fertilizer recommendations. If nutrient balance is not properly evaluated in intensive grain production farming systems it may endanger its sustainability. More conclusive results from this long-term project will be possible with time. Brazil-53 Sources <strong>and</strong> Rates of Phosphorus in a Cultivation System Integrating Crop <strong>and</strong> Pasture Production in the State of Parana Project Leader: Adriel Ferreira da Fonseca, Ponta Grossa State University Department of Soils, Ponta Grossa, Parana. E-mail: adriel@uepg.br The integration of crop <strong>and</strong> pasture production (ICP) within the same area, using no-tillage cultivation systems, is becoming popular in Brazil due to its agronomic advantages. Phosphorus is a key nutrient in these systems <strong>and</strong> soils in the state of Parana are generally low to medium in bioavailable P. The main purpose of this research is to evaluate the effects of P rates <strong>and</strong> sources (water-soluble <strong>and</strong> water-insoluble) on soil quality, plant mineral nutrition, forage, grain, <strong>and</strong> meat yields in an integrated crop-livestock system under no-till. The site has been under no-till for five years. Treatments included three sources of P [triple superphosphate (TSP), magnesium thermophosphate (MTP), <strong>and</strong> Arad reactive rock phosphate (RP)] <strong>and</strong> three rates of P (60, 120, <strong>and</strong> 180 kg total P 2 O 5 /ha), with all sources applied prior to seeding the winter crop. The trial also included a control, with no P applied, <strong>and</strong> three treatments supplying each source at 90 kg P 2 O 5 / ha applied prior to seeding the spring-summer crop. IPNI Interpretive Summaries 45
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