ASSESSMENT OF NET NITROGEN MINERALISATION FROM REPEATED APPLICATIONS OF CATTLE-SLURRY AND MINERAL ..

Our goal was to see how repeated applications of cattle slurry and mineral fertiliser affected net N mineralisation rates in a Mediterranean forage system with maize silage (spring-summer) and Italian ryegrass (autumn-winter) for silage. Between May 1997 and May 2000, a field research was conducted on a commercial dairy-cattle farm in Northwest Portugal. Five different treatments were used: Control with no N fertiliser (T0); one application of cattle-slurry at maize sowing with 187 (T1) or 340 (T2) kg total N ha-1 year-1; two applications, 258 kg total N ha-1 at maize and 150 kg total N ha-1 at ryegrass sowing plus application of 190 kg total N ha-1 to maize and 50 kg total N ha-1 to ryegrass as mineral fertiliser, totaling 648 kg total N ha-1 year-1 (T3) (T4). In each treatment, net N mineralisation was assessed in the soil layer 0-30 cm. Mineralisation owing to cattle-slurry application to soil released significant amounts of nitrogen (160-290 kg N ha-1 year-1), with apparent net N mineralisation ranging between 45 and 95 percent of the total N applied. The use of mineral fertiliser resulted in the immobilisation of 23% of the total N applied. The information gathered in this study could be used to increase manure-N efficiency by managing N fertilisation.

Please see the link :- https://www.ikprress.org/index.php/JOGAE/article/view/594