Drivers of global nitrogen emissions

Nitrogen is crucial for sustaining life. However, excessive reactive nitrogen (Nr) in the form of ammonia, nitrates, nitrogen oxides or nitrous oxides affects the quality of water, air and soil, resulting in human health risks. This study aims to assess the drivers of Nr emissions by analysing six determinants: nitrogen efficiency (Nr emissions per unit of production), production recipe (inter-sectoral dependencies), final demand composition (consumption baskets of households), final demand destination (consumption vs. investment balance), affluence (final consumption per capita) and population. To this end, we construct a detailed multi-regional input-output database featuring data on international trade between 186 countries to undertake a global structural decomposition analysis of a change in global Nr emissions from 1997-2017. Our analysis shows that nitrogen efficiency has improved over the assessed time-period, however affluence, final demand destination and population growth have resulted in an overall increase in Nr emissions. We provide a global perspective of the drivers of nitrogen emissions at a detailed country level, and breakdown the change in emissions into contribution from domestic footprint and rest-of-world footprint. We highlight that food production coupled with growing international trade is increasing Nr emissions worldwide.

The Effects of Interventions Targeting Increased Organic Seed Use—The Cases of Perennial Ryegrass in England and Durum Wheat in Italy

To meet policy goals targeting increasing the share of organic agriculture, an organic seed needs to be provided. Currently, this is far from being the case. This study investigates two cases of important crop country combinations in organic agriculture, namely perennial ryegrass in South-West England and durum wheat in Italy. A novel multi-agent value chain approach was developed to assess public and private-sector interventions aiming at increasing organic seed use. Phasing out of derogations for non-organic seed comes with 2–7% gross margin losses at the farm level. Seed producers and breeders profit by 9–24%. Mitigating measures can be subsidies of 28 €/ha or price premiums of 12 €/ton at the farm gate for durum wheat, in the case of durum wheat in Italy, and subsidies of 13 €/ha or price premiums of 70 €/ton for lamb meat, in the case of perennial ryegrass in England. Further mitigating measures are the promotion of farm-saved durum wheat seed and investments in breeding for better nitrogen efficiency in organic perennial ryegrass seed production.

Effect of using cassava as an amylopectin source in low protein diets on growth performance, nitrogen efficiency and postprandial changes in plasma glucose and related hormones concentrations of growing pigs

This study was aimed to explore the effect of using cassava as an amylopectin source in low protein (LP) diets on growth performance, nitrogen efficiency and postprandial changes in plasma glucose and related hormones concentrations of growing pigs. Three animal experiments were included in the present study. Treatments included corn-soybean meal LP (Corn LP), corn-cassava-soybean meal LP (Corn + Cassava LP), and cassava-soybean meal LP (Cassava LP). The in vitro digestion proved that Corn + Cassava LP and Cassava LP diets induced more rapid starch digestion and glucose release, compared with Corn LP diet. The results of animal experiments are as follows: Cassava LP diet caused the most rapid changes in plasma glucose and relevant hormones concentrations after a meal. And it decreased the concentrations of fasting plasma insulin, glucagon, and leptin concentrations compared with other treatments (P < 0.05). These modulationes above led to a strong desire to eat and increased feed intake and then weight gain in growing pigs fed Cassava LP diet. Besides, feeding Cassava LP diet caused diarrhea, increased noxious gas release from feces, and increased concentrations of fecal isobutyrate and isovalerate (P < 0.05). Compared with Corn LP group, Corn + Cassava LP group showed significantly decreased urinary nitrogen (P < 0.05) and improved post-absorptive amino acid utilization efficiency. In conclusion, the use of cassava as an amylopectin source in LP diets could modulate glucose absorption and related gut secreted hormones secretion, subsequently strengthened the desire to eat, improved growth performance, and enhanced nitrogen efficiency in growing pigs.

Quinoa (Chenopodium quinoa Wild.) Seed Yield and Efficiency in Soils Deficient of Nitrogen in the Bolivian Altiplano: An Analytical Review

Quinoa is a strategic crop due to its high N content and its adaptability to adverse conditions, where most of the soils are deficient of nitrogen (N). The central question in this review was the following: How can quinoa yield low levels of nitrogen in the soils of Altiplano? This question was unraveled based on different factors: (1) fertilization effect on productivity, (2) fertilization limits, (3) uptake and assimilation of nitrogen parameters, (4) monoculture practice effect, and (5) possible sources and strategies. One hundred eleven articles of different scientific platforms were revised and data were collected. Information from articles was used to calculate the partial factor productivity for nitrogen (PFPN), the apparent use efficiency of N (APUEN), available nitrogen (AN), and nitrogen content harvested in grains (HarvN). Quinoa responds positively to fertilization, but differences in yield were found among irrigated and rainfed conditions. Quinoa can produce 1850 kg grains ha−1 with 50 kg N ha−1 under irrigated conditions, and 670 kg grains ha−1 with 15 kg N ha−1 in rainfed conditions. Quinoa increases seed yield and HarvN increases N fertilization, but decreases nitrogen efficiency. In Altiplano, without nitrogen fertilizer, the quinoa yield relies on between 500 and 1000 kg ha−1, which shows that in the soil, there are other nitrogen sources.

Feeding Strategies to Reduce Nutrient Losses and Improve the Sustainability of Growing Pigs

The efficiency of pig production using nutrients has increased over the years. Still, better efficiency of nutrient utilization can be achieved by feeding pigs with diets adjusted to their estimated requirements. An increase in nutrient efficiency of utilization represents economic gains while maximizing environmental performance. The objective of this paper is to review the impact of different methods of diet formulation that provide farm animals with the amount of nutrients to satisfy their needs while minimizing nutrient excretion and greenhouse gas emissions. Diet formulation is one tool that can help to maximize nitrogen and energy utilization by decreasing crude protein content in diets. The use of local feedstuff and non-human-edible products (e.g., canola meal) associated with synthetic amino acid inclusion in the diet are valuable techniques to reduce carbon footprint. Precision feeding and nutrition is another powerful tool that allows not only daily tailoring of diets for maximal nutrient efficiency of utilization but also to reduce costs and improve nitrogen efficiency of utilization. In this review, we simulated through mathematical models the nitrogen and energy efficiency of utilization resulting from crude protein reduction in the diet. An 8% crude protein reduction in the diet can increase nitrogen efficiency of utilization by 54% while costing 11% less than a control diet without synthetic amino acids. The same reduction in crude protein represented a major improvement in available energy due to the decrease of energetic losses linked to protein deamination. Urinary and hindgut fermentation energy losses were 24% lower for pigs fed with low-protein diets when compared to control diets. In terms of modern feeding techniques and strategies, precision feeding and nutrition can decrease nitrogen excretion by 30% when compared to group phase feeding. The benefits of feeding pigs with low-protein diets and precision feeding techniques are additive and might result in a 61% nitrogen efficiency of utilization. There is room for improvement in the way nutrient requirements are estimated in pigs. Improving the understanding of the variation of nutrient utilization among pigs can contribute to further environmental gains.

Potensi Bahan Alami dalam Menekan Produksi CH4 dan N2O dari Tanah Sawah

Low nitrogen efficiency is one of the sources of greenhouse gas (GHG) emissions from rice fields. Methane (CH4) and nitrous oxide (N2O) emissions could be controlled by nitrification inhibitors (NI). However, NI that has been commercialized is expensive. Therefore, some natural materials should be developed as NI that is low cost, easy to use, low N2O and CH4, and eco-friendly. The objective of this study was to observe the effect of natural NI on the production potential of CH4 and N2O from paddy soil. The experiment in the laboratory was arranged in a factorial design (2 × 7 × 3 replication). The first factor was soil types (inceptisols and vertisols), and the second factor was natural NI (control, Cocos nucifera, Camellia sinensis, Coffea robusta, Curcuma domestica, Ageratum conyzoides). The results showed that the average CH4 production from the natural NI in the inceptisols and vertisols ranged 0,014-1,710 mg CH4 g soil-1 and 0,002-0,337 mg CH4 g soil-1, respectively. Application of natural NI reduced 32-69% CH4 production compare to control. Redox potential affected CH4 production. The chemical compound of the natural NI affected CH4 production in the soil. The application of coffee waste, coconut husk, tea waste, and Ageratum conyzoides reduced 60,71; 54,61; 64,83 dan 64,16% of N2O production in Inceptisols compare to control, respectively. Application of natural NI could contribute to save the environment because it decreased GHG production in paddy soil. Keywords: greenhouse gas, inceptisols, incubation experiment, natural nitrification inhibitors, vertisols

Double Coating as a Novel Technology for Controlling Urea Dissolution in Soil: A Step toward Improving the Sustainability of Nitrogen Fertilization Approaches

This research introduces a novel technology for reducing ordinary urea (OU) dissolution by developing double-coated urea (DCU) using phosphate rock (PR) as an outer layer to reduce its hydrolysis and sodium thiosulfate (STS) as an inner layer to inhibit the urease enzyme and nitrification process. Due to the double coating, the nitrogen content of DCU was lower than that of the OU (36.7% vs. 46.5%). The ultramorphological analysis using scanning electron microscopy (SEM) indicated that the controlled coating of urea, resulting from the outer layer of PR, was due to the adhesive effect of urea formaldehyde (UF), which was used as a glue. In addition, the transmission electron microscopy (TEM) analysis of the DCU revealed its high degree of agglomeration. The mechanical hardness of DCU was higher compared to that of OU (1.38 vs. 1.08 kgf). The seven-day dissolution rate test showed that OU reached 100% dissolution on the fifth day. The rate of DCU, however, was significantly lower (32% dissolution in the seventh day). Cumulative NO3− and NH4+ losses from a clay soil sample reached 68.3% and 7.6%, respectively, with OU measuring 40.5% compared to 4.9% for DCU 70 days after application. Field experiments showed a significant improvement in the marketable yield and agronomic nitrogen efficiency (ANE) of maize grains and zucchini fruits fertilized with DCU. Furthermore, the macro and micronutrient concentrations in maize grains and zucchini fruits showed an increase in the plants fertilized with DCU. In summary, double coating can be introduced as a novel technique to control urea dissolution in soil.

Milk Urea Concentration to the Evaluation of Nitrogen Efficiency Transformation on Dairy Farms

The aim of this study was to evaluate the effects of nutrition on the milk urea nitrogen (MUN) concentration; on the transformation of N in the farm’s conditions; and there-by allow the milk urea nitrogen concentration to serve as a tool to maximize the protein nutrition and the metabolism of the cows. The relations evaluated by linear or multiple regression confirmed that the highest nutritional effects of the crude protein (CP) on the MUN concentration, which represented a 69.3 % variation in the MUN content. According to the CP content in the total mix ration (TMR) and MUN content (3150 milk samples) under farm conditions, a regression relationship was determined for the estimated of MUN (mg.dl–1) = –13.2 + 0.16 × CP (g.kg–1 dry matter). For multiple regression, the rate of variation expressed by this relationship increased to 72 for nutrient content and 78.3 % for nutrient intake in the TMR. The efficiency of nitrogen utilization (ENU) determined by calculations based on the MUN content according to the regression equations represented a negative correlation (P < 0.0001; R2 = 0.854) with respect to the CP content in the TMR and that the increased CP content by 1 % in the range of 14 to 18 % in the TMR decreased the ENU by 1.48 %. Validation of the models for prediction of nitrogen transformation (ENU) for practical application on the farms determined the best equation, which used the available data from the routine analysis of Breeding services of Slovakia. After taking into consideration of our breeding conditions, it was confirmed that the equation of ENU had taken into account the MUN, in addition to the amount of the milk produced.