Dried Pig Manure from a Cogeneration Plant as a Fertilizer for Nitrate Vulnerable Zones

Abstract

Nitrate vulnerable zones (NVZs) are areas considered to be at high risk of water pollution due to an excess of nitrates and, according to European regulations, codes of good agricultural practice are to be implemented by farmers, such as reducing doses of the applied fertilizers, or the use of fertilizers that minimize nitrate leaching. In this work, the influence of organic fertilization with dried pig manure (DPM) as compared to mineral fertilization with ammonium sulfate nitrate with 3,4-dimethylpyrazole phosphate nitrification inhibitor was studied in a barley crop planted in a NVZ in Fompedraza (Valladolid, Spain). Organic and mineral fertilizers were applied at different rates (85, 133 and 170 kg N·ha −1 ·year −1 vs. 90 and 108 kg N·ha −1 ·year −1 , respectively) over a three-year period, in a randomized complete block design with six treatments and four blocks. DPM-based fertilization resulted in a 65% increase in crop yield as compared to the control soil, reaching 1800 kg·ha −1 for an application rate of 85 kg N·ha −1 ·year −1 . Higher DPM rates were found to increase the electrical conductivity and assimilable phosphorus, potassium, magnesium and organic matter contents, but did not lead to yield enhancements. Final nitrate and ammonium concentrations were lower than 10 mg·kg −1 and 20 mg·kg −1 , respectively, and no increase in soil salinity or heavy metal pollution was observed. DPM fertilization should be supplemented with small doses of inorganic fertilizers to obtain crop yields similar to those attained with mineral fertilization.

Incorporation of Manure into Ridge and Furrow Planting System Boosts Yields of Maize by Optimizing Soil Moisture and Improving Photosynthesis

“…In subtropical China, the threshold for long-term application of pig manure from an environmental safety perspective would be 3.6 t ha −1 [33]. However, in Valladolid, Spain, the highest yields were attained at an application rate of 9.5 t ha −1 for swine manure, much higher than the rate (6 t ha −1 ) used in the study [11]. Also, there were studies showing that pure manure application resulted in lower N availability in the early stages of crop development as it had a lower speed of nutrient release than mineral NPK did.…”

“…This method is regarded as a feasible approach to keep the rate of grain gain with zero growth of chemical fertilizers consumption. Also, manure amendment has the potential to boost yields through improving soil structure, and enhancing the capacity of water retention [11]. For example, on a degraded tropical Alfisol in south western Nigeria, it was reported that pure poultry manure application at 5 t ha −1 significantly increased maize yield by 60% and soil organic matter by 45%, compared with the application of N fertilizers at 100 kg ha −1 [12].…”

“…However, most studies showed that yields were lower with pure manure application as compared with mineral fertilizers because of lower availability of nitrogen in organic [13]. It has been confirmed that manure fertilization should be supplemented with small doses of chemical fertilizers to sustain or improve crop yields [11]. Previous studies reported that using compost at 10 t ha −1 to replace 50% of inorganic N achieved maximum grain yield (6.96 t ha −1 ) of rice in a slit loam soil in India [14].…”

Effect of Dried Pig Manure Fertilization on Barley Macronutrients and Sodium in a Nitrate Vulnerable Zone

“…Mineral fertilization treatments would result in the highest values of N content (Maleki-Farahani et al 2011;Wilczewski 2014), which shows a positive correlation with the amounts of N applied by mineral fertilization (up to 140 kg ha −1 ) (Wilczewski 2014). Although organic fertilization treatments typically lead to lower values, because of the greater difficulty to supply an adequate amount according to the needs of the plant (Maleki-Farahani et al 2011;Sánchez-Báscones et al 2019), there are exceptions in which organic fertilization treatments have reached similar values to those attained with mineral fertilization (Agegnehu et al 2016), or even higher values (Moreno et al 1996) (see Table 6).…”

“…However, the use of organic waste as fertilizers in agricultural soils can immobilize the nitrate content due to their organic matter content (Sánchez-Báscones et al 2019), and may increase the Na content, thus increasing soil salinity (Li-Xian et al 2007) and negatively affecting crop yield.…”