Productivitat de cultius extensius i fertilitat i qualitat de sòls associades a les aplicacions de dejeccions ramaderes en un sistema agrari mediterrani

S’estudien els efectes a llarg termini (7-12 anys) de les aplicacions de dejeccions ramaderes sobre el rendiment i qualitat de blat de moro en regadiu i cereal d’hivern en secà i sobre la qualitat del sòl en sistemes agrícoles mediterranis. La producció de blat de moro és òptima aplicant fems de boví en fons (30 Mg ha-1) i N mineral (150-200 kg N ha-1) en cobertora. Aplicar majors dosis de fems, sense N en cobertora, permet produccions altes però amb dosis de N superiors a les permeses actualment. Per blat i ordi aportar purins abans de la sembra contribueix a augmentar les produccions de cereal d’hivern i el contingut en proteïna del gra. Aportacions afegides de N mineral en cobertora incrementen la producció de gra i el contingut en proteïna, però disminueixen la densitat i el pes del gra. Aplicacions anuals de dejeccions, tant en reg com en secà, milloren diferents paràmetres indicadors de la qualitat del sòl: augmenten l’estabilitat dels agregats, el contingut en C orgànic en la fracció lleugera de la matèria orgànica del sòl, la porositat i l’abundància de cucs de terra, respecte la fertilització amb adobs minerals.Se estudian los efectos a largo plazo (7-12 años) de las aplicaciones de deyecciones ganaderas sobre el rendimiento y calidad del maíz en regadío y el cereal de invierno en secano y sobre la calidad del suelo en sistemas agrícolas mediterráneos. La producción de maíz es óptima aplicando estiércol de bovino en fondo (30 Mg ha-1) y N mineral (150-200 kg N ha-1) en cobertera. Aplicar mayores dosis de estiércol, sin N en cobertera, permite producciones altas pero con dosis de N superiores a las permitidas actualmente. Para trigo y cebada aportar purines antes de la siembra contribuye a aumentar las producciones de cereal de invierno y el contenido en proteína del grano. Aportaciones añadidas de N mineral en cobertera incrementan la producción de grano y el contenido en proteína, pero disminuyen la densidad y el peso del grano. Aplicaciones anuales de deyecciones, tanto en riego como en secano, mejoran diferentes parámetros indicadores de la calidad del suelo: aumentan la estabilidad de los agregados, el contenido en C orgánico en la fracción ligera de la materia orgánica del suelo, la porosidad y la abundancia de lombrices de tierra, respecto la fertilización con fertilizantes minerales.We studied the long term effects (7-12 years) of manure application on yield and quality of irrigated maize and rainfed winter cereals and on soil quality in Mediterranean agricultural systems. Maize yield is optimized by applying dairy cattle manure (30 Mg ha-1) at presowing and mineral N (150-200 kg N ha-1) as sidedress. Higher manure rates, without sidedressing, allow high yielding but using more N than permitted at the moment. For wheat and barley, presowing applications of pig slurry contributes to increase winter cereals yields and grain protein content. Further application of mineral N at sidedressing increases yield and protein content but decreases grain density and weight. Annual manure application, for both irrigated and rainfed systems, improves, in respect mineral fertilization, several parameters that are indicators of soil quality: increases aggregate stability, organic C content in the light fraction of soil organic matter, porosity and earthworms abundance

Short Communication: Laboratory assessment of ammonia volatilization from pig slurries applied on intact soil cores from till and no-till plots

Aim of study: Agricultural activities are the main source of volatilized ammonia (NH3). Maximum rates are reached within a few hours after slurry application. This study aimed to evaluate the influence of soil texture, tillage and slurry dry matter (DM) on NH3 volatilization.Area of study: Mediterranean semiarid environments (NE Spain).Material and methods: Ammonia volatilization from pig slurry directly applied on the soil surface was quantified in the laboratory, in soil samples from two experimental sites with different soil textures: silty loam and sandy loam. Field treatments consisted of two tillage management practices: till by disc-harrowing or no-till. At topdressing (cereal tillering), tillage treatments were combined with slurries of different DM contents applied onto the silty loam soil. Measurements were done for two cereal cropping seasons and during the period of maximum NH3 flux (12 h after slurry application). A photoacoustic analyzer was used.Main results: Slurry spreading at sowing resulted in low volatilization (0.7-9% of NH4+-N applied) as it also did at topdressing (0.3-1.4% of NH4+-N applied). At sowing, ammonia volatilization from high DM slurry (>7.5%) was significantly enhanced by no-till in both soils. At topdressing, this result was also found in records on silty loam soil. No differences were found between tillage systems when slurry of low DM content was applied, whatever the soil texture and application moment. Although NH3 volatilization was probably affected by the laboratory conditions, the comparisons between treatments were still valuable.Research highlights: Ammonia volatilization abatement can be improved (<1 kg NH3-N ha-1) if fertilization is done after crop establishment using low DM slurries (<3.5%).info:eu-repo/semantics/publishedVersio

Long-term fertilization with dairy cattle slurry in intensive production systems: effects on soil porosity and pore morphology

In Mediterranean environments, livestock effluents might improve soil physical properties. The study was located in an intensive crop production system of northwest Spain. After nine consecutive years of dairy cattle slurry (DCS) use as fertilizer, the aim of the experiment was to evaluate the impacts of DCS on soil porosity and pore shape. Soil texture was loam. The applied DCS rates were equivalent to 170 and 250 kg N ha−1 (170DCS and 250DCS, respectively) and they were complemented with mineral N up to 450 kg N ha-1 (two crops). A nonfertilized control was included. Digital binary images were obtained from soil thin sections. Pores with an apparent diameter (AD) &gt;30 µm were analysed. The 250DCS treatment improved soil porosity (&gt;30 µm): it doubled in comparison with the 170DCS and the control. The application of DCS favored the presence of pores with an AD &gt;400 µm, the roughness for AD &gt;100 µm and the elongation in the AD interval of 100-200 µm. From the study, the 250DCS treatment is recommended as it increases macroporosity (compaction reduction) and produces more elongated and tortuous pores, which will be a constraint for fast drainage but it will be advantageous in coarse textured soils.In Mediterranean environments, livestock effluents might improve soil physical properties. The study was located in an intensive crop production system of northwest Spain. After nine consecutive years of dairy cattle slurry (DCS) use as fertilizer, the aim of the experiment was to evaluate the impacts of DCS on soil porosity and pore shape. Soil texture was loam. The applied DCS rates were equivalent to 170 and 250 kg N ha−1 (170DCS and 250DCS, respectively) and they were complemented with mineral N up to 450 kg N ha-1 (two crops). A nonfertilized control was included. Digital binary images were obtained from soil thin sections. Pores with an apparent diameter (AD) &gt;30 µm were analysed. The 250DCS treatment improved soil porosity (&gt;30 µm): it doubled in comparison with the 170DCS and the control. The application of DCS favored the presence of pores with an AD &gt;400 µm, the roughness for AD &gt;100 µm and the elongation in the AD interval of 100-200 µm. From the study, the 250DCS treatment is recommended as it increases macroporosity (compaction reduction) and produces more elongated and tortuous pores, which will be a constraint for fast drainage but it will be advantageous in coarse textured soils