The objective of this work was to evaluate the biomass (leaves and stems) production of annual and cover crops sown as second crop, and its effects on soybean yield in succession. The experiment was carried out in the 2014/2015 and 2015/2016 crop seasons. Soybean was sown in the crop season and in the second crop, in a randomized complete block design, in nine production systems (treatments) consisting of annual crops (corn, sunflower, and cowpea) and cover crops (Pennisetum glaucum, Crotalaria breviflora, C. spectabilis, Urochloa ruziziensis, Cajanus cajan, Stylosanthes sp., and U. brizantha), which were grown in monocropping or intercropping systems, besides fallow as a control. Monocropped P. glaucum and U. ruziziensis showed a faster establishment and growth of plants, higher-total biomass and soil cover rate in the 2014 crop season. In 2015, corn intercropped with U.ruziziensis and C.spectabilis, and sunflower with U.ruziziensis stood out for total biomass production during flowering and after harvesting of corn and sunflower grains. Biomass composition in the systems showed greater proportions of stems than of leaves, and C.spectabilis stood out after senescence. Sown as a second crop, C. spectabilis promotes yield increase of soybean grown in succession in the no-tillage system.
For mitigation of negative effects of human activities on the soil density, the use of cover crops in no-tillage system (NTS) has been strongly recommended. This study aims to evaluate the shoot and root development of Urochloa ruziziensis subjected to soil density levels in dystrophic Oxisol. The experiment was conducted in a greenhouse with a completely randomized design, with five treatments and four replications. The treatments consisted of U. ruziziensis submitted to five levels of soil density (1.0, 1.2, 1.4, 1.6 and 1.8 Mg m -3 ), twenty experimental units in total. The Urochloa ruziziensis showed reduced plant height, leaf area and number of leaves with increasing soil density, resulting in morphological and physiological changes from densities higher than 1.6 Mg m -3 . However, these results demonstrate the ability of this species to break the compacted ground and form biopores. The Oxisols value of 1.4 Mg m -3 is restrictive for the plant growth and development.
RESUMOObjetivando avaliar a influência de fontes e doses de N em cobertura sobre o desempenho do milho safrinha, após a soja, conduziu-se a presente pesquisa em Itiquira -MT, na safrinha de 2014, num Latossolo Vermelho distrófico muito argiloso. Os tratamentos foram dispostos em delineamento de blocos ao acaso, em esquema fatorial incompleto (3x4)+1, sendo: três fontes de N (ureia tradicional, ureia com aditivo e nitrato de amônio), quatro doses de N (30, 60, 90 e 120 kg ha de N via fosfato monoamônico e 1,0 kg ha -1 de Zn. Foram mensurados parâmetros morfológicos e produtivos da cultura. Ocorre incremento do diâmetro de colmo, altura de planta e de inserção de espiga, índice SPAD, comprimento e diâmetro de espiga, massa de mil grãos e produtividade de grãos com o aumento nas doses de N. Recomenda-se a aplicação de 120 kg ha -1 de N em cobertura do milho safrinha, sob semeadura direta, independente da fonte nitrogenada, desde que aplicadas em condições favoráveis ao aproveitamento do N pelas plantas. PALAVRAS-CHAVE: nitrato de amônio, ureia, Zea mays L. NITROGEN SOURCES AND RATES ON OFF-SEASON MAIZE CROPSUCCEEDING SOYBEAN CROP ABSTRACT This study aimed at evaluating the broadcast application of N sources and rates on the agronomic performance of off-season maize succeeding soybean. The research was conducted at the Experimental Station of the MT Foundation in Itiquira -MT, in the off-season of 2014, on a clayey Rhodic Haplustox. The experimental design was in randomized blocks with treatments in a factorial arrangement (N sources x N rates) plus one additional treatment (3x4)+1. Treatments included three sources (traditional urea, urea with additive and ammonium nitrate) and four rates of N (30; 60; 90 and 120 kg ha
- The objective of this work was to evaluate the effects of crop production systems under no-tillage and with surface liming, after 10 to 11 years, on nematode populations and soybean (Glycine max) grain yield. Twelve treatments were established in a randomized complete block design, with four replicates. The plots consisted of three production systems (monoculture, soybean followed by fallow in the off-season; crop succession, soybean followed by millet in the off-season; and crop rotation, soybean followed by rattlebox, Urochloa ruziziensis, and corn, each one in an off-season), and the subplots, of four rates of surface dolomitic limestone (0.0, 2.0, 4.0, and 8.0 Mg ha-1). Crop rotation and sucession favors a higher soybean grain yield, reducing the population of Heterodera glycines in the soil and roots and increasing the populations of Helicotylenchus spp. The increment in surface limestone rates reduces soybean grain yield, with an increase in the population of H. glycines in the soil and roots and a decrease in the populations of Pratylenchus brachyurus and Helicotylenchus spp.
RESUMO Nos últimos anos, os nematóides das lesões radiculares (Pratylenchus brachyurus), têm causado significativas perdas na cultura da soja, sobretudo, em regiões do Centro-oeste. Entretanto, são poucas as informações de genótipos de soja resistentes à infestação do nematoide das lesões radiculares. Objetivo do trabalho foi avaliar a reação de dezoito genótipos de soja infectados com população de Pratylenchus brachyurus. O delineamento experimental utilizado foi inteiramente casualizado (DIC), constituído por dezenove tratamentos e 6 repetições. Os genótipos estudados foram: W791RR,
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.