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The usual application of high 4-14-8 NPK fertilizer rates in the potato planting furrows, independently of the soil fertility or nutritional cultivar requirements, has become a paradigm in Brazil. However, the 4-14-8 NPK formula does not always meet the crop needs, and can unbalance the availability of nutrients in the soil. The objective of this study was to evaluate the tuber yield and economic results of ‘Atlantic’ potato as affected by rates of 4-14-8 and 6-30-6 NPK formulas applied in the planting furrows. The rates of both NPK formulas were calculated to reach P2O5 rates of 210, 420, and 630 kg ha-1. At each P2O5 rate, the 6-30-6 formula resulted in less 30% N and 65% K2O in the planting furrow compared to 4-14-8 formula. A randomized complete block design in a factorial scheme (2×3)+1, including an unfertilized furrow control, with three replications was used. Only the use of 6-30-6 formula increased the total tuber yield of ‘Atlantic’ potato. The marketable tuber yield reached higher levels (29.8 t ha-1) with higher P2O5 rate (440 kg ha-1) using the 6-30-6 than 4-14-8 formula. The fertilizer rates and formulas NPK did not affect specific gravity of marketable tubers. Therefore, the use of a fertilizer more concentrated in P2O5 that favors smaller contributions of N and K (as the 6-30-6 formula studied in this work) provides lower costs, and greater operational efficiency and profits in relation to the 4-14-8 formula traditionally used for the potato crop. RESUMO A aplicação usual de altas doses do fertilizante NPK 4-14-8 nos sulcos de plantio da cultura da batata, independentemente da fertilidade do solo ou das necessidades nutricionais da cultivar, tornou-se um paradigma no Brasil. Contudo, a fórmula 4-14-8 nem sempre atende as necessidades da cultura e pode desequilibrar a disponibilidade de nutrientes no solo. O objetivo deste trabalho foi avaliar as produtividades de tubérculos e os resultados econômicos da batata cultivar Atlantic afetada por doses das fórmulas NPK 4-14-8 e 6-30-6 aplicadas no sulco de plantio. As doses de ambas as fórmulas NPK foram calculadas para atingirem doses de 210, 420 e 630 kg ha-1 de P2O5. Em cada uma das doses de P2O5, a fórmula 6-30-6 resultou em 30% menos N e 65% menos K2O no sulco de plantio do que a fórmula 4-14-8. Foi utilizado um delineamento em blocos casualizados, em esquema fatorial (2×3)+1, que incluiu um controle sem adubação no sulco, com três repetições. Apenas a utilização da fórmula 6-30-6 aumentou a produtividade total de tubérculos da cultivar Atlantic. A produtividade de tubérculos comercializáveis atingiu maior nível (29,8 t ha-1) com maior dose de P2O5 (440 kg ha-1) utilizando-se a fórmula 6-30-6 comparada com a fórmula 4-14-8. As doses e fórmulas de fertilizantes NPK não afetaram o peso específico dos tubérculos comercializáveis. Portanto, o uso de um fertilizante mais concentrado em P2O5 que favorece aportes menores de N e K (como a fórmula 6-30-6 estudada neste trabalho) proporciona menores custos, e maiores eficiência operacional e lucros em relação à fórmula 4-14-8 tradicionalmente usada na cultura da batata.

The objective of this work was to evaluate the residual effects of occasional soil tillage in a 17-year-old, no-tillage system, associated with liming and nitrogen fertilization, on the crop yields and chemical properties of a very clayey Oxisol in the South of Brazil. A randomized complete block design in split-split plots was used, with two soil managements (with or without plowing), two liming treatments (with or without the required dose to raise base saturation to 70%), five N doses applied on side-dress (0, 1, 2, 4, and 6 times the recommended amounts), and four replicates. A rotation system was used with corn and soybean in the summer, and with wheat and black oats in the winter. The residual effects of occasional soil tillage in a consolidated no-tillage system do not supplant those of liming applied on soil surface, in periods of water deficit, which subsidizes the recommendation to maintain the system consolidated. Excess N fertilization in no-tillage, with liming applied only on soil surface, may harm wheat yield, acidifying the topsoil and leaching Mg2+ to the subsurface soil layers. Without liming, soil acidification is more intense with N fertilization, which, however, favors the accumulation of organic matter on soil surface in a consolidated no-tillage system.

The organic production system for potato is usually limited by the occurrence of diseases and nutrient shortage. In these cases, fresh grass mulch and organic fertilization can interact in the foliar late blight infestation and increase the yield and quality of marketable potato tubers, in the organic production system. Aiming to validate this hypothesis, four poultry litter doses (0 Mg ha-1, 10 Mg ha-1, 20 Mg ha-1 and 30 Mg ha-1), which were incorporated into the soil at the pre-planting stage of organic grown potato combined with the presence and absence of fresh mulch (60 Mg ha-1) composed of chopped Elephant grass, were tested. The incorporation of poultry litter into the soil at the pre-planting of potato or the use of fresh grass mulch after the potato hilling inhibits the late blight infestation on leaves, in the organic system. The application of fresh grass mulch after the hilling operation enhances the effect of organic fertilization at the pre-planting of potatoes. The pre-planting application of poultry litter increases the yield and decreases the specific gravities of marketable potato tubers in association with fresh grass mulch. The use of poultry litter at pre-planting and fresh grass mulch improve the sustainable potato cropping in the organic production system. KEYWORDS: Solanum tuberosum, Phytophthora infestans, chicken manure, organic agriculture.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:46:58Z No. of bitstreams: 1 S0100-204X2007000600011.pdf: 1062590 bytes, checksum: 5cc85d3a51aa8e539efafdfb64dbba09 (MD5) Made available in DSpace on 2013-08-22T18:46:58Z (GMT). No. of bitstreams: 1 S0100-204X2007000600011.pdf: 1062590 bytes, checksum: 5cc85d3a51aa8e539efafdfb64dbba09 (MD5) Previous issue date: 2007-06-01 Made available in DSpace on 2013-09-30T19:36:36Z (GMT). No. of bitstreams: 2 S0100-204X2007000600011.pdf: 1062590 bytes, checksum: 5cc85d3a51aa8e539efafdfb64dbba09 (MD5) S0100-204X2007000600011.pdf.txt: 33777 bytes, checksum: 51df8276472302371e5cf1d8b315074e (MD5) Previous issue date: 2007-06-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:17:06Z No. of bitstreams: 2 S0100-204X2007000600011.pdf: 1062590 bytes, checksum: 5cc85d3a51aa8e539efafdfb64dbba09 (MD5) S0100-204X2007000600011.pdf.txt: 33777 bytes, checksum: 51df8276472302371e5cf1d8b315074e (MD5) Made available in DSpace on 2014-05-20T13:17:06Z (GMT). No. of bitstreams: 2 S0100-204X2007000600011.pdf: 1062590 bytes, checksum: 5cc85d3a51aa8e539efafdfb64dbba09 (MD5) S0100-204X2007000600011.pdf.txt: 33777 bytes, checksum: 51df8276472302371e5cf1d8b315074e (MD5) Previous issue date: 2007-06-01 O objetivo deste trabalho foi avaliar, em casa de vegetação, os efeitos de doses de esterco bovino e de calcário na formação de mudas de guanandi (Calophyllum brasiliense Cambèss.). Foram avaliadas quatro doses de cada fator, combinadas em esquema fatorial 4x4. O delineamento experimental foi inteiramente ao acaso com quatro repetições, e cada parcela continha cinco mudas. O substrato foi formado pela mistura, em volume, de oito partes de subsolo e duas partes de areia, e doses de esterco correspondentes a 0, 2, 4 e 6 partes que, em massa, equivalem a 0, 101, 175 e 229 kg m-3. As doses de calcário foram calculadas para elevar a saturação por bases (V%) a 20, 35, 50 e 65%. Aos 120 dias, foram avaliados: altura, diâmetro do colo, número de folhas, área foliar e matéria seca das partes aérea e radicular das mudas. em substrato constituído de subsolo+areia, a calagem e a adubação com esterco bovino não são necessárias para produção de mudas de guanandi. The effects of cattle manure and lime levels in substrate were evaluated to produce guanandi (Calophyllum brasiliense Cambèss.) seedlings in greenhouse conditions. Four levels of each factor were evaluated, in a factorial scheme 4x4. The experimental design was completely randomized with four replicates, each plot with five seedlings. The substrate was obtained by the mixture of eight subsoil parts and two sand parts (v:v). The manure was applied in 0, 2, 4 and 6 parts, in volume, that correspond, in mass, to 0, 101, 175 and 229 kg m-3. Lime doses were calculated to increase the base saturation degree near to 20% (original subsoil sample), 35, 50 and 65%. Seedlings harvest was performed 120 days after transplant, when height, stem diameter, leaf number, leaf area, shoot and root dry matter were evaluated. For substrate constituted by subsoil+sand, the liming and the cattle manure are not necessary to produce guanandi seedlings. Universidade Estadual Paulista Fac. de Ciências Agrárias e Veterinárias Dep. de Solos e Adubos Unesp Fcav Dep. de Produção Vegetal Universidade Estadual Paulista Fac. de Ciências Agrárias e Veterinárias Dep. de Solos e Adubos Unesp Fcav Dep. de Produção Vegetal