Contact/s:
Elena Bortolazzo
e.bortolazzo@crpa.it
Efficient Agronomic Use of Slurry as Top Dressing to Optimize Nitrogen Use and Reduce Emissions
Italy
Italy, Continental
Top dressing,
Precision spreading,
Nitrogen use efficiency
Thematic Areas
Production System/s
Summary for Practicioners on the Main Finding(s)/Innovative solution(s)
The efficient use of livestock effluents as top dressing represents a solution to address the problems related to the spreading of these matrices on various crops, such as winter cereals, maize, forage mixtures, and permanent grassland. Top dressing distribution carried out with suitable technical equipment allows the fertilizing potential of livestock effluents to be enhanced, applying them at the times and in the doses required by the crop. This practice makes it possible to reduce nutrient losses into water and the atmosphere thanks to an increase in nitrogen use efficiency. In recent
years, innovative agricultural machinery has been developed for top dressing distribution, capable of operating even when soil conditions are not optimal, thus achieving an extension of the spreading windows without compromising agricultural yields.
Some technological solutions are:
Fertigation with Pivot or Ranger: It uses microfiltered digestate mixed with irrigation water. This prevents nozzle clogging and provides the plant with readily available ammoniacal nitrogen.
Band spreading and trailing shoes: Low-pressure boom systems that distribute the effluent in surface bands or with shallow incorporation. They reduce crop fouling and ammonia emissions. They can be installed on tankers or fed via an umbilical system from a buffer tank stationed at the edge of the field.
“Talpa” system: A self-propelled injector equipped with high ground clearance and narrow wheels. It allows for the injection of effluents between the rows of crops up to 1.5 meters tall, such as maize and sorghum, without damaging the vegetation.
Summary for Practicioners in Native Language
L’uso efficiente degli effluenti zootecnici in copertura rappresenta una soluzione per rispondere alle problematiche legate allo spandimento di queste matrici su diverse coltivazioni, quali ad esempio cereali autunno vernini, mais, miscugli foraggeri e prato stabile. La distribuzione in copertura effettuata con mezzi tecnici idonei permette di valorizzare le potenzialità fertilizzanti degli effluenti, distribuendo nei momenti e nelle dosi richieste dalla coltura. Questa pratica permette di ridurre le perdite di nutrienti nelle acque e in atmosfera grazie ad un incremento di efficienza di utilizzo dell’azoto. Negli ultimi anni sono state sviluppate macchine agricole innovative per la distribuzione in copertura in grado agire anche quando le condizioni del suolo non sono ottimali, ottenendo così un ampliamento delle finestre di spandimento senza tuttavia compromettere le produzioni agricole.
Alcune soluzioni tecnologiche sono:
Fertirrigazione con Pivot o Ranger: Impiega digestato microfiltrato miscelato all’acqua irrigua. Questo evita l’intasamento degli ugelli e fornisce alla pianta azoto ammoniacale prontamente disponibile.
Band spreading e trailing shoes: Sistemi a barra a bassa pressione che distribuiscono il refluo a bande superficiali o con un leggero interramento. Riducono l’imbrattamento vegetale e le emissioni di ammoniaca. Possono essere installati su carri botte o alimentati tramite un sistema ombelicale da una “balia” stazionata a bordo campo.
Sistema “Talpa”: Un interratore semovente dotato di un’elevata luce libera da terra e ruote strette. Permette l’interramento degli effluenti nell’interfila di colture alte fino a 1,5 metri, come mais e sorgo, senza danneggiare la vegetazione.
Additional Information
Efficient top-dressing fertilisation maximizes crop yields by applying nitrogen at the right time, dose, and place, and promotes nutrient relocation, encouraging arable crop farms without livestock to use organic matrices instead of synthetic fertilizers.
The previously described distribution techniques guarantee different performances depending on pedoclimatic conditions, farm characteristics, and crops on which they operate. However, it is important to evaluate some aspects before applying these techniques at the farm level:
Regarding the fertigation system with Pivot or Ranger, it is necessary to adopt appropriate pre-treatment systems for livestock effluents and manage the distribution system in order to avoid nozzle clogging. These systems are ideal if the farm has underground pipes; otherwise, transport and logistics with a tanker must be considered.
The trailing shoe system is more effective in reducing emissions but could, under certain soil conditions and on specific crops, affect yields. In relation to the size of the plots, their location, and the farm’s logistical conditions, booms with the correct operating widths must be chosen. The farm layout and the size of contiguous land plots characterized by the same crop operations are aspects that determine the convenience of using a boom fed
by an umbilical hose or a boom installed on the back of tankers or on self-propelled vehicles. For example, small plots with uniform crops or interspersed with obstacles prefer the type of boom mounted on the tanker.
For the umbilical system, the type of hose connecting the roadside buffer tank with the spreading system is the critical point of the system because, on one hand, it must be robust to resist dragging and abrasion, but on the other hand, it must be highly flexible to guarantee the turning radius for the tractor at the headland and to avoid damaging the crops.