The increasing demand for sustainable agricultural practices has driven growing interest in organic fertilizers derived from waste streams as alternatives to mineral fertilizers. This study evaluated, in a pilot trial, the effectiveness of using raw digestate, composted digestate and composted sewage sludge in a crop rotation over two consecutive years of maize and Italian ryegrass. Crop yield, forage quality, and soil physicochemical properties were assessed to determine the potential of these recycled organic nitrogen sources. The results differed between the two species of forage. In maize, organic fertilizers maintained yield and forage quality comparable to chemical fertilization, while composted sewage sludge significantly increased average plant height. These findings indicate that recycled organic amendments can partially or totally replace mineral nitrogen fertilizers, contributing to nutrient recycling and waste valorization within a circular economy framework. In contrast, Italian ryegrass showed lower yield under organic fertilization than under chemical fertilization, suggesting that additional management strategies may be required to optimize nutrient availability for this crop. Furthermore, raw digestate application tended to increase soil pH, which may provide benefit subsequent crop. Overall, the results suggest that digestate and sludge-based fertilizers are promising alternatives for maize performance, although their effectiveness in Italian ryegrass requires additional strategies.

En una finca experimental de Asturias (Norte de España; Arco Atlántico), con praderas de Lolium perenne y Trifolium repens, utilizadas en pastoreo rotacional y ensilado, aprovechada por un rebaño de vacas frisonas con partos de invierno, se determinó durante 18 años sucesivos la producción y calidad fisicoquímica de la leche según diversas suplementaciones, que variaban según dosis (en función de la producción o aporte fijo) y modalidades de concentrado (rico en almidón o en fibra digestible). A cada lote de animales se asignaron diferentes parcelas de pastoreo manteniendo una misma carga de 2,2 UGM/ha. Paralelamente a estos ensayos de larga duración, se efectuaron balances en energía y nitrógeno sobre vacas individualizadas en nave metabólica. Los resultados se emplearon para modelizar la producción y composición de la leche según semana de lactación mediante la función gamma incompleta con resultados concordantes. Las vacas en base a forraje produjeron 4.221 kg leche/vaca·año con 3,68 % de grasa y 3,01 % de proteína. Las novillas no pudieron permanecer sin suplementación y la respuesta a la misma se situó entre 1,55‑1,82 kg leche/kg MS concentrado, influyendo más la dosis que la naturaleza del concentrado. El aporte fijo de concentrado (5 kg/cabeza·día) resultó la suplementación más efectiva y el concentrado con fibra de alta digestibilidad elevó el contenido en grasa de la leche.

The metabolites secreted by probiotics or released after their lysis are called postbiotics. They provide physiological benefits to the host, preventing the colonisation of pathogens by improving the intestinal environment for beneficial commensal bacteria, which reduces the incidence of digestive disorders and improves the immune system. The aim of this work was to evaluate the addition of postbiotics to dairy cow rations during the transition period on nutrient digestibility, composition, and milk yield. The effects of two postbiotics were evaluated in twelve Friesian cows from 30 days before calving to two months of lactation. The animals were randomly allocated to two treatment groups: control (CT) and supplemented with postbiotics (PC and PR). Feeding was ad libitum with 60/40 of forage/concentrate ratio on dry matter basis. Daily feed intake and milk production were recorded individually throughout the study. Two digestibility balances were performed, one before parturition and one after parturition. Colostrum was sampled at first milking and milk was sampled weekly. Data were analysed using a mixed mode in R software 4.4.1. The results suggest that postbiotic supplementation in late gestation and early lactation increase the voluntary intake of dry matter, especially in the PR treatment, with higher apparent total tract digestibility of dry matter, organic matter and neutral detergent fibre. Both treatments including postbiotics induced an increase in colostral immunoglobulin concentration. Milk production of cows receiving the PC treatment was the highest, with high fat and protein yields and a higher persistence of the production curve throughout the lactation.

Production and quality of milk were determined for 18 successive years according to different supplements, in an experimental farm in Asturias (Northern Spain; Atlantic Arc), provided with Lolium perenne and Trifolium repens sown meadows, used for rotational grazing and silage by a herd of Friesian dairy cows with grouped winter calvings. The concentrate used for supplementation varied according to dose (depending on yield or fixed contribution) and concentrate type (rich in starch or digestible fiber). Different grazing plots were assigned to each dairy group, maintaining the same stocking rate of 2.2 UGM/ha. Parallel to these long-term trials, energy and nitrogen balances were carried out on individualized cows in a metabolic house. The results in this regard were used to model milk production and composition by lactation week using the incomplete gamma function with concordant results. Forage-based cows produced 4,221 kg milk/cowyear with 3.68 % fat and 3.01 % protein. The heifers could not remain without supplementation and the response to it was between 1.55-1.82 kg milk/kg DM concentrate. The concentrate dose had more influence on milk production than the nature of this. The most effective supplementation was the fixed concentrate intake of 5 kg/headday and the highly digestible fiber concentrate increased the milk fat content.

Digestibility, energy and nitrogen balances for eight years were determined in green forage of perennial ryegrass and white clover meadows, and in addition to first cut (in trench silo) and second cut (in big bales) silages. The temporary grassland was characteristic of the central coastal land of Asturias (Atlantic Area). The trials were carried out on individualized Frisian cows in metabolism stalls. Six production animals participated in each one with ad libitum forage. These animals were divided into three groups according to management: two of them with forage as the only diet (control group) and four supplemented with concentrate (three different concentrates) twice a day, across the four dosing scales throughout the years. The relative ingestibility, fill units and substitution rate were determined. The relative ingestibility (scale 0-1) of green forage was 0.87 in March and decreased to 0.71 in October (p < 0.05), while in terms of fill units/kg dry matter, they results were 1.01-1.24, respectively. For first and second cut silages, the relative ingestibilities were 0.70 and 0.82, respectively, and the milk fill units were 1.26 and 1.08 (not significant). The substitution rate was 0.37, without significant differences between concentrates. Results from this study suggest that the evaluated temporary grassland has a very good potential for voluntary forage intake in dairy cattle, with an adequate response to supplementation with concentrate.

Durante ocho años se determinó la digestibilidad, balances en energía y nitrógeno en forraje verde de pradera de raigrás inglés y trébol blanco, así como de los ensilados de primer corte (en silo trinchera) y segundo corte (en rotopacas). La pradera era característica de la zona costera centro oriental de Asturias (Arco Atlántico). Los ensayos se realizaron sobre vacas frisonas con partos de invierno individualizadas en nave metabólica. En cada uno intervinieron seis animales en producción, con forraje a voluntad: dos como lote testigo con forraje como dieta única y cuatro suplementados con concentrado dos veces al día, con un total de siete suplementaciones distintas, a partir de tres concentrados diferentes y cuatro escalas de dosificación. Los datos recogidos permiten determinar la ingestibilidad relativa, el valor lastre en vacuno lechero y el nivel de sustitución forraje: concentrado. La ingestibilidad relativa (escala 0‑1) del forraje verde resultó 0,87 en marzo y descendió hasta 0,71 en octubre (p < 0,05), mientras que en términos de unidades lastre leche/kg de materia seca, fueron 1,00‑1,25, respectivamente (p < 0,01). Para los ensilados de primero y segundo cortes, las ingestibilidades relativas fueron respectivamente 0,70 y 0,82 y las unidades lastre leche 1,26 y 1,08 (no significativo). El nivel de sustitución resultó de 0,37, sin diferencias significativas entre concentrados. Se concluye que la pradera evaluada presenta buena capacidad de ingestión en vacuno lechero y bajo efecto sustitución, hecho que posibilita una adecuada respuesta a la suplementación con concentrado.

In an experimental farm located in Asturias (North of Spain; Atlantic Area; 43 degrees 28' 50 '' N, 5 degrees 26' 27 '' W, 10 m above sea level), with sown meadows of Lolium perenne and Trifolium repens, in a system of rotational grazing and silage for Friesian cows with winter calving, was determined along eight consecutive years the chemical composition of offers and refusals, the in vivo digestibility of the forages, as well as the effect of different supplementations on the total diet digestibility. Each year, the herd was distributed in three groups: a control group without supplementation and another two treatments to contrast different doses (according milk yield or flat rate) and modalities of concentrate (two concentrate rich in starch and another one in digestible fiber). Two cows of each groups were allocated into metabolic stalls to control of voluntary intake of forage, concentrate dose, excretion of feces, urine and milk, plus live weight and body condition score control. Samples were taken daily for nutritive analysis and estimation of in vivo digestibility. It was detected that the evaluated grass from North of Spain has a nutritional limitation due to organic matter digestibility loss in summer (59.4 % in August, respect 74.4-77.5 % in spring and 73.2-78.3 % in autumn, p < 0.001). Nevertheless, it was surprising the high neutral detergent fiber digestibility results (annual range 51.8-76.0 %). The in vivo organic matter digestibility of concentrates values ranged from 85.5 % and 74.4 % for starch-rich concentrates and 71.5 % for the concentrate rich in high digestibility fiber.

The temporary ley of Lolium perenne and Trifolium repens is widely used for milk production in temperate-humid areas. Its nutritional value depends on its chemical composition, ingestibility and subsequent digestive and metabolic use. On the central eastern coast of Asturias, data are available on the evolution of its chemical composition and digestibility. The general objective of this paper was to obtain information on the use of energy and nitrogen ingested. The specific objectives were to determine, throughout the year and for a period of 12 years, the evolution of the energy units, the urinary losses of nitrogen and the recovery of the same in milk, with forage as a single diet or supplemented with different scales and modalities of concentrate. During spring, metabolizable energy at maintenance level (MJ), milk forage units according to INRA 2018 and net lactation energy at feed level 3 (Mcal), per kg of dry matter, ranged respectively between 11.1-11.7; 0.93-1.01 and 1.31-1.49. In summer, they were reduced to 10.2-8.9; 0.87-0.69 and 1.18-0.84. In autumn, spring values gradually recovered. The grass silages had values similar to those of summer grass. Energy supplementation with concentrates significantly elevated metabolicity, feeding level and recovery of raw energy ingested in milk. Nitrogen supplementation significantly increased the recovery of nitrogen ingested in milk and with 15 % crude protein on dry matter, the excretion of nitrogen into the environment was reduced. The evaluated pasture has high potential for milk production in compliance with EU regulations.

The livestock sector must find solutions to reduce the feeding costs and meet the challenge for a more sustainable production system in line with the European Green Deal requirements. The aim of this study was to evaluate the effect of including legume silage on voluntary intake in dairy cows, milk production, and composition. Three total mixed rations (TMR) based on faba bean (FB), Italian ryegrass (IR), or faba bean–Italian ryegrass intercrop (FBIR, 60:40) silages were used in feeding trials of dairy cows during two consecutive years. Nine Friesian cows were randomly allocated in three groups, following a 3 × 3 Latin square design with three diets for three periods. TMR were offered ad libitum in addition to eighteen hours of grazing daily and extra concentrate during milking. No differences were observed in dry matter intake. Diets did not affect milk production or composition, except for urea content, with a higher urea excretion in FB diet. Fatty acid profile was different in milk from cows feeding FB, with a significantly lower content of saturated fatty acids and a higher content of conjugated linoleic acid than milk produced with FBIR and IR diets.

Less than 30% of dairy cattle's nitrogen ingested is retained in milk. Therefore, large amounts of nitrogen can be excreted in manure and urine with a potential environmental impact. In addition, some legume forages can be more susceptible to proteolysis during the silage process than grasses, and dairy cows fed these legume silages would excrete a larger quantity of nitrogen in slurry. The objectives of this work were to evaluate the amount of nitrogen excretion in dairy cows fed different protein levels and legume silages with a view to improve the slurry quality as a co-product that can be used as fertilizer. Two double 3 × 3 Latin square trials were carried out in order to study three different protein levels (high, medium, and low) and three different silages (grass, faba bean, and field pea). Dry matter intake, milk production, and composition were not affected by treatments. The excretion of ammonia-N in the urine was almost four times lower in the diet with the lowest protein level. The ammonia-N in the urine was twice as high with the pea silage than faba bean and grass silages. In conclusion, the diet containing 13% of protein meets the protein requirement for lactating cows producing 31 kg daily, with low nitrogen excretion in the urine, and the main pathway for the excretion of surplus nitrogen from legume silages is through urine and the metabolization of pea silage protein goes toward ammonia-N.

The aim of this study was to evaluate the fermentation characteristics and nutritive value of two interesting forage species (maralfalfa and tagasaste) ensiled with molasses and beet pulp as additives.Ensilability parameters and chemical composition were analysed in two different stages of growth in maralfalfa (flowering and vegetative growing) and two different branch diameters in tagasaste (branches > 5mm, branches ≤ 5mm).According to ensilability results, four combinations with additives (two for tagasaste and two for maralfalfa) were ensiled at laboratory scale microsilos, in order to evaluate fermentative and nutritive parameters in two different conservation periods (35d and 70d).Tagasaste showed high dry matter (DM) content and fermentability ratio (FR) but a very low sugar content (WSC).Maralfalfa showed poor initial ensiling characteristics, low DM and WSC and high BC (buffering capacity).Supplementing tagasaste with molasses improves the fermentative composition in mini-silos with adequate ammonia-N and lactic acid concentrations detected.Moreover, the addition of beet pulp and molasses to the ensiled maralfalfa allows achieving the pH value under 4 and NH3˗N content below 10%, with an interesting content of lactic acid improving the fermentation quality of silage.

The European Common Agricultural Policy promotes the sustainable use of soils through the principle of cross-compliance that links direct payments to good farming practices. Thus, it is necessary to find sustainable alternatives to the conventional management for forage production in the Atlantic Arc dairy farms. Two alternative managements (faba bean in monoculture—FB—and faba bean–Italian ryegrass intercrop—FBIR) were cultivated with organic fertilization during two consecutive years, and compared to the conventional management (Italian ryegrass in monoculture—IR—under chemical fertilization) as winter crops. Maize was used as the summer crop to complete the rotations using organic and chemical fertilization, respectively. The forage yield of winter fodder was quantified. Soil samples and summer harvests were performed to analyse the physico-chemical and biological parameters. The best forage yield corresponded to FBIR with 9.2 t dry matter (DM) ha−1 vs. 7.2 and 5.7 t DM ha−1 for FB and IR, respectively. The soil organic matter did not show significant differences among treatments, suggesting that it may be a poor indicator of the management influence on edaphic quality in the short term. Biological indicators were more sensitive and faster to differentiate among managements than chemical indicators. Earthworm abundance was higher in FB and FBIR than IR (p < 0.001), and consequently, soil infiltration was improved with the alternative management (13.90 vs. 2.08 and 0.90 min for IR, FB and FBIR, respectively, p < 0.01). As a result, the soil health diagnosis of the agroecosystem was better for alternative management.

ResumenEn una finca experimental de Asturias (Norte de España; Arco Atlántico; 43° 28' 50'' N, 5° 26' 27'' W, 10 m s.n.m.), con pradera de Lolium perenne y Trifolium repens, para pastoreo rotacional y ensilado, aprovechada por vacas frisonas con partos de invierno, se determinó durante ocho años sucesivos el contenido en principios nutritivos de las ofertas y rechazos de forrajes, así como las digestibilidades in vivo de los mismos y el efecto de diversas suplementaciones sobre la digestibilidad de la ración total.Cada año, el rebaño se dividió en tres grupos: un lote testigo sin concentrado y otros dos para contrastar diferentes dosis (según producción o aporte fijo) y modalidades de concentrado (dos ricos en almidón y uno rico en fibra digestible).Dos vacas de cada lote se alojaban en plazas metabólicas para control de ingestión voluntaria de forraje, dosis de concentrado, excreción de heces, orina y leche, y, peso vivo y condición corporal.Diariamente se tomaron muestras para análisis de composición química y cálculo de digestibilidad in vivo.Los resultados mostraron que la hierba evaluada presentaba una limitación nutricional por la pérdida de digestibilidad de la materia orgánica en verano (59,4 % en agosto, más baja aún que la de los ensilados, frente a 74,4-77,5 % en primavera y 73,2-78,3 % en otoño, p < 0,001).No obstante, destacó la elevada digestibilidad de la fibra neutro detergente de los forrajes (intervalo anual 51,8-76,0 %).Los valores de digestibilidad in vivo de la materia orgánica de los concentrados oscilaron entre 85,5 % y 74,4 % para los dos concentrados ricos en almidón y del 71,5 % para el concentrado rico en fibra de alta digestibilidad. Palabras clave:

Dairy systems based on grass and forages are widely spread throughout the European Atlantic Arc and they have an influence on milk quality. Likewise, legumes are a key element in the farms to improve cows’ diet and farm feed self-sufficiency. The aim of this study was to evaluate the effect of the legumes in the diet and the feeding system (pasture-based vs. confined) on milk production and composition. An assay was performed with 18 Friesian cows randomized into two management groups (grazing or confined). Three total mixed rations based on Italian ryegrass, faba bean or field pea silages were offered ad libitum for nine continuously housed cows or during two hours after each milking for another nine grazing cows. Regardless of type of silage, grazing cows had higher dry matter intake and milk production than confined cows. Likewise, grazing cows produced milk with a lower concentration of protein and urea than confined cows. The dairy cows fed total mixed rations based on both legume silages had a milk fat with a higher proportion of unsaturated fatty acids, especially with the inclusion of faba bean silage in the diet. The results demonstrate that the profile of fatty acids and antioxidants is related to the feeding system in dairy cows. Grazing directly influenced the composition of milk, decreasing the proportion of saturated fatty acids and increasing the content of unsaturated fatty acids, as CLA, and the antioxidants, as lutein and β-cryptoxanthin.

This study evaluated the ensilability, fermentation metabolites and nutritive value of fresh waste tomatoes with two different additives namely, dehydrated beet pulp and cereal straw. Initially, the comparative ensilability parameters were assessed in two different types of waste tomato fruits, i.e. interior market (Ti) and ecological (Te) tomatoes. Subsequently, as per the observed ensilability attributes, Ti was selected for further investigation. Accordingly, the waste tomatoes were ensiled as such (Ti) or in combination with 25% dehydrated beet pulp (Ti-DBP) and 25% cereal straw (Ti-CS) in laboratory microsilos. The quality and stability of the silages were assessed over time i.e., on d 35 and 70. In both the treatments, 3.5 L of formic acid was added per ton of silage to improve the fermentation. Both waste tomato types, ecological and interior tomatoes, showed high water-soluble carbohydrates content, but low DM, buffering capacity and fermentability ratio. Chemical analysis data showed significant differences (P<0.05) in the composition (except for OM content) between the silage materials before ensiling, with or without as additives. Both the silages presented good fermentative attributes with significant differences only in the concentrations of ammonia (P=0.004) and formic acid (P<0.001). In contrast, the chemical composition data showed significant differences (P<0.001) in all parameters analyzed except DM and OM contents. Moreover, no differences were detected between ensiling periods (35 and 70 d). In general, waste tomatoes ensiled with dehydrated beet pulp showed better fermentative and nutritional quality than silage with cereal straw.

This study analyzed potential causes of a 40% mortality rate observed in a flock of endangered Xalda sheep, indigenous to the province of Asturias in northern Spain. We found that productive and reproductive parameters of the flock were also severely affected. In order to diagnose the cause of mortality and illness in the sheep, we examined the animals and their living conditions. We found high concentrations of nitrate in animal serum, well water and the surrounding pastures. Based on these findings and the absence of a geological source for nitrogen in the paddock, we believe that inappropriate management of manure in neighboring dairy farms resulted in nitrate toxicity in the Xalda sheep. This study highlights the importance of good practices in manure management and the need to monitor nitrate toxicity in pastures. It also highlights the importance of anthropogenic factors on the conservation of animal genetic resources.

Three trials were conducted to study the effect of including in the ration of dairy cows the intercrop faba bean-rapeseed or Italian ryegrass silages on feed intake, milk quality and enteric methane emissions. Ten lactating Holstein cows, randomly allocated in two groups, were used in each trial in a crossover design. Dry matter intake and milk yield were recorded daily for each data period. Milk was sampled for analyses three times per period. Enteric methane emission was estimated applying a model that includes bodyweight, dry matter intake, nutritional values of feeds and milk composition. Concentrate and grass intake did not differ between treatments, while total mixed ration intake was higher with Italian ryegrass silage. Milk yield and protein concentration also increased with the Italian ryegrass treatment. The milk urea concentration was higher with the faba bean and rapeseed diet. Fatty acid profiles were affected by feeding strategy. Thereby, t11 18:1, c9 18:1 and total unsaturated fatty acid were higher when the intercrop silage was fed. As consequence, atherogenicity index and thrombogenicity index were lower under that treatment. Estimated enteric methane emissions did not differ between treatments. In conclusion, faba bean-rapeseed intercrop can be an alternative to Italian ryegrass to feed dairy cows. The rations formulated with the intercrop silage have potential to improve the milk fatty acid content, and show healthier profiles for consumers. However, it would be useful to study the protein content of these crops to avoid possible excess urea in milk and to maintain sustainable milk yield and milk protein content.

The optimization of milk production includes a rational use of forages, respect for the environment and offers the best quality to consumers. Milk production based on grass and forages produces healthier milk and it is widely spread throughout the Atlantic arc to maximize milk yield per hectare. However, the mode of offering the grass can have a major influence on milk composition. The aim of this study was to evaluate the effect of grass supply mode (grazing, zero-grazing or ensiling) on dairy cows' performance, with particular reference to fatty acids and fat-soluble antioxidants concentration. A three by three Latin square experiment was performed with 18 dairy cows. Experimental treatments consisted of exclusive feeding with grass silage and zero-grazing, both offered ad libitum indoors, or grazing for 24 h. The results showed that grazing cows had a higher dry matter intake and greater milk yield than cows feeding on grass silage and zero-grazing, as well as higher concentrations of protein, lactose, nonfat-solids and urea in milk than housed cows. Milk fat from grazing cows had a higher proportion of unsaturated fatty acids than from cows feeding on grass silage and zero-grazing, with significant differences in the proportion of vaccenic and rumenic acids. The 18:1 trans-11 to 18:1 trans-10 ratio is proposed as biomarker to identify the milk produced from the management system of grazing cattle. Milk from grazing cows had a greater proportion of lutein than cows eating grass silage, with the zero-grazing system having intermediate values. In conclusion, the mode of grass supply affects fatty acid and antioxidant profiles of milk.

Aim of study: To evaluate agronomic performance and changes on soil chemical properties in two types of managements: conventional or sustainable. Area of study: Principality of Asturias, Spain. Material and methods: On a sandy-clay-loam texture soil, three winter forage legumes (faba bean, red clover and white lupin), in monoculture or mixed with Italian ryegrass and with organic fertilization (sustainable management) versus Italian ryegrass in monoculture and inorganic fertilization (conventional management) were evaluated during three consecutive years. After the harvest in spring, the rotations were completed with maize crop with the purpose to evaluate the effect of the sustainable management on forage yield and soil chemical parameters. Main results: The results showed that faba bean and red clover in monoculture and mixed with Italian ryegrass had better edaphic quality than Italian ryegrass in monoculture, and white lupin in monoculture or mixed with Italian ryegrass. Faba bean in monoculture and mixed with Italian ryegrass, both with organic fertilization, could be competitive crops since both had yields comparable to Italian ryegrass in monoculture with inorganic fertilization. Research highlights: Current agricultural practice could be changed for a more sustainable management system, including organic fertilization and legume crops.

Soil fertility building measures should be explored at the short and long-term for an adequate evaluation of their impact on sustaining yields and of its environmental consequences in crop rotations under organic farming. For such a purpose, process-based crop models are potential useful tools to complement and upscale field observations under a range of soil and climatic conditions. Organic rotations differ in soil fertility dynamics in comparison to conventional farming but very few modelling studies have explicitly considered this specific situation. Here, we evaluate the FASSET model to predict the effects of different fertility management options in organic crop rotations on dry matter (DM) and nitrogen (N) yield, and soil N dynamics, including N2O emissions. For that, we used data from seven short and long-term field experiments in different agro-climatic environments in Europe (Norway, Denmark, Poland, Switzerland, Italy and Spain) including climate, soil and management data. Soil fertility building measures covered fertilization type, green manures, cover crops, tillage, crop rotation composition and management (organic or conventional). Model performance was evaluated by comparing observed and simulated values of crop DM and N yield, soil mineral N and nitrous oxide (N2O) emissions using five complementary statistical indices. The model closely reproduced most observed DM and N yield trends and effects of soil fertility building measures in arable crops, particularly in cereals. Contrary, yields of grass-clover, especially N, were generally reproduced with low degree of accuracy. Model performance for simulating soil mineral N depended on site and the availability of soil and management information. Although high uncertainty was associated to the simulation of soil N dynamics, differences of cumulative N2O emissions between fertility building measures were reflected in model outputs. Aspects for modelling improvement include cover crop growth and decomposition, biological N fixation (BNF) or weed and pest soil-crop interactions. It is concluded that FASSET can be successfully used to investigate the impact of fertilization type, green manures, tillage and management (organic or conventional) on crop productivity and to a certain extent on soil N dynamics including soil N2O emissions at different soils and climates in organic farming in Europe.