Compost as a Substitute for Mineral N Fertilization? Effects on Crops, Soil and N Leaching

Abstract

A three-year study was conducted to test the fertilization properties of different types of compost as the total or partial mineral nitrogen fertilization substitute in an herbaceous crop succession (Zea mays L., Triticum aestivum L. and Helianthus annus L.). Four types of compost (i. green cuttings and depuration sludge, ii. green cuttings, organic fraction of municipal wastes and other organic materials, iii. green cuttings, iv. green cuttings and organic fraction of municipal wastes) and eight fertilization treatments (combining: unfertilized control, 100% mineral fertilization, 100% compost, and 50% compost +50% mineral fertilization) were evaluated in terms of: (i) crop yields and nitrogen uptake, (ii) soil organic carbon and nitrate nitrogen soil contents variation, and (iii) residual nitrate nitrogen leached at the end of the experiment. Maize grain yield ranged from 5.2 ± 1.0 Mg ha−1 to 7.4 ± 0.7 Mg ha−1 with the highest value in the mineral fertilization treatment and the lowest values in the 100% compost fertilization. Wheat and sunflower grain yields were not significantly different among control, mineral, compost, or mineral/compost fertilization treatments with average values of 5.1 ± 0.7 Mg ha−1 and 2.3 ± 0.3 Mg ha−1, respectively. Cumulative crop yield at the end of the three years was not affected by the compost type, but was affected by fertilization treatment (highest values with mineral and 50% compost +50% mineral fertilization). The compost application did not highlight a relevant effect on soil organic carbon. Under 100% of compost fertilization, the crops did not take up a large amount of the N supplied, but it did not generate an increase of NO3-N leaching in the percolation water. Obtained results show the good fertilization properties of compost whereas the amendment property was not relevant, probably due to the low rates applied and the short experimental period.

Evolution of Composting Process in Maize Biomass Revealed by Analytical Pyrolysis (Py-GC/MS) and Pyrolysis Compound Specific Isotope Analysis (Py-CSIA)

“…Today, the interest in this practice has been widely applied since it is known to provide multiple benefits to soils, especially in agricultural ones (depleted in organic matter, subjected to severe erosion and water scarcity problems), besides having relevance as carbon sequestration agent [3,4]. Furthermore, compost material has been proven to have a significant fertilizer value, depending on crop requirements, amendment properties, and its production process [5][6][7].…”

Laser Irradiation Effects at Different Wavelengths on Phenology and Yield Components of Pretreated Maize Seed

“…The use of physical factors for controlling the influence of biological behavior during development and storage of different cultures is a modern trend in combining the intensification of plant technologies with ecological requirements [10]. Most physical factors that only modify physiological and biochemical processes in seeds are also safe for the environment [11][12][13], for instance, improving agriculture practices, such as by using chemical fertilizer and regular weed control [14]; however, this can affect the environment [15]. In contrast, laser stimulation does not cause harmful changes in the environment, which is of great importance in organic and integrated agriculture [16,17].…”

Reducing Topdressing N Fertilization with Variable Rates Does Not Reduce Maize Yield

“…This field experiment allowed us to test the effectiveness of the proximal sensor of advanced and available technology in reducing N fertilizer with no negative impact on maize grain yield. The regional and EU incentives make the technology accessible thanks to a discounted purchase because the correct use of the sensor aims at reducing the mineral N fertilization targeting limited N leaching and volatilization losses [38,39]. This experiment offered us the opportunity to operate under actual field conditions being characterized by high SOC and N contents due to the long-term application of on-farm available manure.…”

“…In an integrated crop and livestock farm system, which is characterized by slurry availability over the year, organic fertilizer should be used to enhance the production efficiency and farmer net return [11], maximize grain yield mainly with the improvement of spatial homogeneity in the field, and improve the quality by increasing the grain protein content [39]. A way to achieve these objectives is to implement precision farming management with the adoption of proximal sensors, as supported by the rural development plan (PSR) of the Lombardy Region, which has recently partly subsidized the equipment purchase by farmers [40,41].…”