Nitrogen balance in a plant-soil system under different cover crop-soybean cropping in Argentina

 Cover crops (CC) provide many benefits for the soil and the following crop but their effects on nitrogen (N) release and balance in continuous no-tillage soybean (Glycine max L. Merr.) production are little known. Estimation of the biological nitrogen fixation (BNF) in intensive agricultural systems under soybean is essential to understanding the N dynamics and to determining the balances and crop demands. This study (2006–2011) was performed on a Typic Argiudoll under no-tillage in the province of Santa Fe, Argentina. The aims were to study the effect of fall winter CC, such as wheat (W), oats (O), oats + vetch (O + V) and vetch (V), on the yield and N-content of the following crop (soybean) and to quantify the contribution of the BNF and N-balance. Three methodologies were used for BNF estimation: 1) a linear regression model between BNF and N-uptake by soybean; 2) the natural 15N abundance in soybean and 3) the average BNF in the Pampa region. Gramineous CC developed more dry matter than pure legume species, with intermediate values for the gramineous-legume mixture. Biological fixation provides 60–70% of absorbed N, according to the estimation method. Within the rainfall range of 500–1000 mm during the soybean cycle, CC did not affect the grain yield or soybean dry matter production. The partial N-balance was always positive, with differences between the techniques used for BNF estimation. Cover crops have contributed to the positive soil N-balance. Gramineous CC stored 22% more N content in the soil surface layer than the others. Cover crops showed 15% higher index of N-stratification on the surface compared to the control soil. Using CC would be an efficient alternative to produce biomass and to supply N to the soil for the subsequent crop

Cover crops Soybean Biological fixation N-balance Mollisol

Landriscini M.R., J.A. Galantini, M.E. Duval, J.E. Capurro. 2019. Nitrogen balance in a plant-soil system under different cover crop-soybean cropping in Argentina. Applied Soil Ecology 133:124-131.

doi: 10.1016/j.apsoil.2018.10.005

Descargar     (en INGLES)         /         Download     (in ENGLISH)

ResearchGate     Journal      Google Drive 

Cover crops reduce environmental impact by improving soil biological properties and crop yield

 

Cover crops (CC) represent a potential practice to reduce the use of herbicides and the impact on the environment. In addition to controlling weeds and increasing crop yields, they allow to increase microbial biomass and activity through the addition of crop residues. The objective of this work was to determine the effects of the inclusion of CC and herbicide application on microbial activity, labile organic matter and crop yield. The assay was done under a soybean - corn rotation system without tillage. It was made on a split plot design with three replicates, where the main factor was the previous crop of the summer crop, a cover crop, and bare fallow (B). The secondary factor was the post-emergence chemical control of weeds during the summer crop, with and without glyphosate applications. The soil sampling was carried out at 10 cm depth during four consecutive crop seasons (2013/2014, 2015/2016; 2016/2017 and 2017/2018), until 15 days after applying the last dose of glyphosate. The biological variables Respiration (R); Fluorescein diacetate (FDA), Acid Phosphatase (AF); and chemical soil variables, particulate organic carbon (POC), particulate organic nitrogen (PON), Anaerobic nitrogen (AnN), and soybean and corn yields were measured. In addition, the environmental impact index for each management was calculated. In general, the inclusion of CC increased R, 51% the FDA and 21% AF; and the applications of herbicide decreased contents of POC by 36%, PON 40% and AnN by 25% in one crop seasons apparently influenced by the temperatures and rainfall. Soybean and corn yields were higher with applications, ardless of the previous crop. However, the plots with CC without herbicide application exceeded the levels of B without application by 30%. The CC favored the biological properties of the soil without modify crops yields, reducing the environmental risk 64% even making applications. On the other hand, the applications of herbicide affected the labile soil organic matter fractions increasing the environmental risk respect to the management without applications. From the evaluated soil conditions, CC used in agricultural systems to promote soil biological properties and crop yields is recommended. This practice reduces environmental impact even in combination with herbicide application.

Triticale, Rye, Vetch, Glyphosate

Boccolini M.F., C.R. Cazorla, J.A. Galantini, P.A. Belluccini, T. Baigorria. 2019. Cultivos de cobertura disminuyen el impacto ambiental mejorando propiedades biológicas del suelo y el rendimiento de los cultivos. RIA (INTA) 45(3) 412-425.

Descargar     (en Español)         /         Download     (in Spanish)

ResearchGate     Journal      Google Drive  

Cover Crops in the Production System

Autumn-winter cover crop effects on yield and corn N accumulation in Southwestern Buenos Aires

Cover crops (CC) have an effect on nitrogen (N) accumulation and on successive crop yields. The aim of this study was to evaluate yields, yield components and N accumulation of maize using as previous crops different CC and evaluating the response to N fertilization. Five experiments were conductedd on a Typic Argiudioll (USDA Soil Taxonomy) of Coronel Suárez. The species used as CC were: Oats (Avena sativa), Hairy vetch (Vicia sativa) and control (chemical fallow). The experimental design consisted of split-plots in three randomized complete blocks, with main plots corresponding to the cover crops treatment and subplots to the fertilizer treatment (N applied at the V4-V6 corn stage). The treatments in the main plots were the CC. The effects of CC varied according to the corn yield component.. Hairy vetch and N fertilization at different rates increased the N absorption efficiency. A greater N absorption was not always related to increases in corn yields, probably due to the climatic variability among years. There was a tendency for greater corn yields with hairy vetch as a preceding cover crop. N application reduced hairy vetch N recovery during the second year and increased N recovery during the first and third year. Fertilizer application effects varied among previous crops with a low response to N when the previous crop was hairy vetch, a variable response when in fallow and a significant response when the previous crop was oats.

Cover crops, corn, hairy vetch, clover, oats, yield, nitrogen.

Sá Pereira E. de, J.A. Galantini, A. Quiroga, M.R. Landriscini. 2014. Efecto de los cultivos de cobertura otoño invernales, sobre el rendimiento y acumulación de N en maíz en el sudoeste bonaerense. Ciencia del Suelo 32 (2) 219-231.

Download   ResearchGate  Journal Web Google Drive  (in SPANISH)

Cover Crops in the Production System

Production and quality of cover crops in soybean monoculture

Cover crops (CC) are an alternative to improve soil organic matter, capture labile nutrients and minimizing its leaching losses during long-term fallows, typical of agricultural systems with high frequency soybean (Glycine max L. Merr.). The objective was to evaluate the production and nutrient content of different CC in simplified system (soybean monoculture) under no-tillage. CC used were: (T) bread wheat (Triticum aestivum L.), (A) oat (Avena sativa L.), (V) vetch (Vicia sativa L.) and (A+V) oat + vetch. Upon drying the CC was determined: production of total aerial dry matter (MS), biochemical composition (cellulose, hemicellulose and lignin), macro- and micronutrients. Dry matter production in T and A ranged between 7.2 and 11.1 Mg ha^-1, differing significantly from V with values between 4.1 and 4.6 Mg ha^-1. Carbon concentration did not differ between CC (43-45% C). The amount of N accumulated in aboveground biomass ranged between 102 and 212 kg N ha^-1, showing differences only between years. The concentration of structural polymers clearly differ between CC species, where T and A showed higher concentrations of cellulose and hemicellulose regarding V. Conversely, V showed higher concentrations of nonstructural carbohydrates and lignin than grasses. Winter grasses as CC were more efficient in producing MS and therefore more effectives to contribute to increased soil organic matter, promoting the recycling of macro- and micronutrients, preventing the leaching of those most labile.

Wheat-vetch, Biochemical composition

Duval, Matías E.; Galantini, Juan A.; Capurro, Julia E.; Beltrán, Marcelo J. 2017. Producción y calidad de diferentes cultivos de cobertura en monocultivo de soja. Ciencias Agronómicas (FCA-UNR) XXIX 7-13.
(View more....)