scholarly journals Cereal straw management: a trade-off between energy and agronomic fate

2015 ◽  
Vol 10 (2) ◽  
pp. 59 ◽  
Author(s):  
Massimo Monteleone ◽  
Pasquale Garofalo ◽  
Anna Rita Bernadette Cammerino ◽  
Angela Libutti
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Crop Residues ◽  
Ghg Emissions ◽  
Cropping System ◽  
Primary Energy ◽  
Nitrous Oxide Emissions ◽  
Straw Management ◽  
Trade Off

Climate change mitigation is the most important driving force for bioenergy development. Consequently, the environmental design of bioenergy value chains should address the actual savings of both primary energy demand and greenhouse gases (GHG) emissions. According to the EU Renewable Energy Directive (2009/28/EC), no direct impacts and no GHG emissions should be attributed to crop residues (like cereal straws) when they are removed from agricultural land for the purpose of bioenergy utilisation. The <em>carbon</em> <em>neutral</em> assumption applied to crop residues is, however, a rough simplification. Crop residues, indeed, should not be viewed simply as a waste to be disposed, because they play a critical role in sustaining soil organic matter and therefore have an inherent C-capturing value. Moreover, considering straws as an energy feedstock, its status of co-product is clearly recognised and its availability could be obtained according to different cropping systems, corresponding to different primary energy costs and GHG emissions. This paper highlights some <em>hidden</em> features in the assessment of agricultural energy and carbon balance, still very difficult to be detected and accounted for. Although they are frequently disregarded, these features (such as long term dynamic trend of soil organic carbon and annual nitrous oxide emissions from the soil) should be carefully considered in assembling the energy and emission balance. By using a crop simulation model, the long-term soil organic matter and annual N<sub>2</sub>O soil emissions were estimated. Consequently, a comprehensive energy and GHG balance was determined in accordance with the <em>life cycle assessment</em> methodology. Contrasting methods of straw management and wheat cultivation were compared: straw retention <em>vs</em> removal from the soil; conventional <em>vs</em> conservation tillage; wheat cropping system as a single-crop or in rotation. The resulting <em>carbon</em> <em>footprint</em> of straws has different magnitudes with respect to the several experimental conditions. By selecting the best agricultural practices, energy from straw can be optimally coupled with grain productions, without detrimental effects on soil fertility. An improved and specifically tailored cropping system is designed to obtain an optimal trade-off.

scholarly journals Roots contribute more to refractory soil organic matter than above-ground crop residues, as revealed by a long-term field experiment

2011 ◽  
Vol 141 (1-2) ◽  
pp. 184-192 ◽  
Author(s):  
Thomas Kätterer ◽  
Martin Anders Bolinder ◽  
Olof Andrén ◽  
Holger Kirchmann ◽  
Lorenzo Menichetti
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Field Experiment ◽  
Crop Residues ◽  
Term Field

Modelling soil organic matter levels after long-term applications of crop residues, and farmyard and green manures

1987 ◽  
Vol 101 (1) ◽  
pp. 21-28 ◽  
Author(s):  
A. M. A. Van der Linden ◽  
J. A. Van Veen ◽  
M. J. Frissel
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Crop Residues ◽  
Green Manures

scholarly journals Evolution of Soil Biochemical Parameters in Rainfed Crops: Effect of Organic and Mineral Fertilization

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Marta M. Moreno ◽  
Carmen Moreno ◽  
Carlos Lacasta ◽  
Ramón Meco
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Biochemical Parameters ◽  
Crop Residues ◽  
Microbial Biomass Carbon ◽  
Cropping System ◽  
Biomass Carbon ◽  
Biological Fixation ◽  
Mineral Fertilization

In organic farming, crop fertilization is largely based on the decomposition of organic matter and biological fixation of nutrients. It is therefore necessary to develop studies conducted to know and understand the soil biological processes for the natural nutrient supplies. The effect of three fertilizer managements (chemical with synthetic fertilizers, organic with 2500 kg compost ha−1, and no fertilizer) in a rainfed crop rotation (durum wheat-fallow-barley-vetch as green manure) on different soil biochemical parameters in semi-arid conditions was investigated. Soil organic matter, microbial biomass carbon, organic matter mineralization, CO2production-to-ATP ratio, and NO3-N content were analysed. Fertilization was only applied to cereals. The results showed the scarce effect of the organic fertilization on soil quality, which resulted more dependent on weather conditions. Only soil organic matter and NO3-N were affected by fertilization (significantly higher in the inorganic treatment, 1.28 g 100 g−1and 17.3 ppm, resp.). Soil organic matter was maintained throughout the study period by the inclusion of a legume in the cropping system and the burying of crop residues. In fallow, soil microbial biomass carbon increased considerably (816 ng g−1), and NO3-N at the end of this period was around 35 ppm, equivalent to 100 kg N ha−1.

scholarly journals Soil organic matter assessments in a long-term cropping system study

2002 ◽  
Vol 33 (13-14) ◽  
pp. 2119-2130 ◽  
Author(s):  
Gary E. Varvel ◽  
Mark A. Liebig ◽  
John W. Doran
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Cropping System ◽  
System Study

Modelling water, nitrogen, and crop yield for a long-term fallow management experiment

1995 ◽  
Vol 35 (7) ◽  
pp. 941 ◽  
Author(s):  
ME Probert ◽  
BA Keating ◽  
JP Thompson ◽  
WJ Parton
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Water ◽  
Cropping System ◽  
Wheat Crop ◽  
Time Step ◽  
Soil System ◽  
N Transformations ◽  
Winter Cereal

Two models that differ markedly in how they represent the crop-soil system have been used to simulate soil processes and crop production in the long-term experiment at Hermitage Research Station, Warwick, Queensland. The experiment was designed to examine the effects of tillage, stubble management, and nitrogen (N) fertiliser on the productivity of a winter cereal-summer fallow cropping system. it commenced in 1968 and the treatments have been maintained until the present. CENTURY operates on a monthly time step, considers all soil N transformations to occur in a single soil layer, and has a very simple crop growth routine that does not deal with crop phenology. APSIM provides a framework whereby a model of a cropping system is configured from component modules, which operate on a daily time step. For simulating the Hermitage experiment, modules to represent the dynamics of soil-water, N, surface residues, and growth of a wheat crop were used. The water and N modules deal with a multi-layered soil, whilst the wheat module develops leaf area, intercepts light, and accumulates and partitions dry matter in response to weather, soil-water, and N. Both models were specified to simulate the whole experimental period (1969-92) as a continuous run. The ability of these models to simulate grain yields, soil-water and drainage, nitrate-N, and soil organic matter were examined. Both models predict, in agreement with the observed data, that for this continuous cereal cropping system there has been a decline in soil organic matter for all the treatments and a reduction through time in the capacity of the soil to mineralise and accumulate nitrate during the fallows. CENTURY performed better than APSIM in predicting the relative yields of the N treatments but was less satisfactory than APSIM for absolute grain yield, soil-water, and drainage. Yield predictions with APSIM were sensitive to carry-over errors in the water balance from one season to the next, so that in some seasons large errors occurred in the predicted relative yields. Both models reproduced the observations well enough to indicate their suitability for providing useful insights into the behaviour of cropping systems where the focus is on depletion of soil fertility.

Impact of long-term wheat production management practices on soil acidity, phosphorus and some micronutrients in a semi-arid Plinthosol

Soil Research ◽  
2013 ◽  
Vol 51 (5) ◽  
pp. 415 ◽  
Author(s):  
P. F. Loke ◽  
E. Kotzé ◽  
C. C. Du Preez
Keyword(s):  
Organic Matter ◽  
Weed Control ◽  
Production Management ◽  
Management Practices ◽  
Crop Residues ◽  
No Tillage ◽  
Straw Management ◽  
Straw Burning ◽  
Semi Arid

Farmers continuously remove crop residues for use as building materials, fuel and animal feed or bedding as well as to avoid difficulties during tillage operations. Therefore, demonstrations of the benefits of recycling crop residues are necessary. The aim with this study was to evaluate the influence of different wheat production management practices on acidity and some essential nutrients from a long-term trial on a Plinthosol in semi-arid South Africa. The trial was set up in 1979, and since then two methods of straw management (unburned and burned), three methods of tillage (no-tillage, stubble mulch, and plough), two methods of weed control (chemical and mechanical), and three levels of nitrogen (N) fertiliser (20, 40 and 60 kg ha–1) have been applied. Soil samples were collected in June 2010 at depths of 0–50, 50–100, 100–150, 150–250, 250–350 and 350–450 mm from plots that received 40 kg N ha–1 and were analysed for pH, phosphorus (P), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn). Results obtained showed that straw burning resulted in higher P and Mn but lower Cu than no-burning. No-tillage, and to some extent stubble mulch, suppressed soil acidification and increased P and Zn compared with ploughing, especially in the surface layers where crop residues accumulate. In contrast, mouldboard ploughing and stubble mulch increased Cu more than no-tillage, possibly due to the strong affinity of organic matter for Cu. Tillage effects on Mn were inconsistent and difficult to explain. Chemical weeding also improved P, probably because of the pesticide application, but resulted in lower pH and Cu values compared with mechanical weeding. Treatment combinations also had an influence on P and, to a lesser extent, on soil pH and Cu, which might be due to the higher organic matter present in no-tilled soils. Irrespective of straw management or weed-control methods, no-tillage resulted in higher P than did ploughing and stubble mulch. Nutrient concentrations and pH values were sufficient for wheat growth under all treatments. However, although the nutrients were highest under straw burning, no-tillage and, to some extent, stubble mulch, wheat yield was higher with unburned straw and mouldboard ploughing. Therefore, an integrated approach from various disciplines is recommended to identify and rectify yield-limiting factors under conservation tillage systems.

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