Dry matter production and nitrogen use efficiency of giant missionary grass in response to pig slurry application

Abstract

-This study assessed the effect of successive applications of pig slurry on the dry matter (DM) production and the nitrogen use efficiency of giant missionary grass along two years. A total of 55, 110, 165, 220 and 275 m 3 of pig slurry/ha/year were applied in order to supply 100, 200, 300, 400 and 500 kg of total N/ha/year, respectively. These treatments were compared with the ammonium nitrate (200 kg of N/ha/year) source of N and with a control (no nitrogen application).Annually, nitrogen was applied in four divided doses, after the cutting of forage grasses, which takes place five times a year.The total DM yield did not differ between years and increased linearly as a function of pig slurry application, ranging from 2,698 kg of DM/ha/year (control) to 11,371 kg of DM/ha/year (275 m The efficiency index of pig slurry ranged from 0.52 to 0.72.

Pig slurry in carpet grass pasture: Yield and plant-available nitrogen

“…The NAE obtained in this study was in the range reported by Vielmo et al (2011) for Tifton 85 (24 to 9 kg DM kg -1 N after fertilization with 144 and 576 kg N ha -1 year -1 , applied with 80 and 320 m 3 of pig slurry, respectively). Similar results were reported by Durigon et al (2002), of 6.6 (autumn) and 20.8 kg DM kg -1 N (spring) for a natural pasture, as well as to those reported by Miranda et al (2012) for giant missionary grass (19.0 kg DM kg -1 N from pig slurry; 30.3 kg DM kg -1 N from ammonium nitrate). The convergence between our results and those reported by these studies reinforces their consistency.…”

“…The PS doses were different between the years as a consequence of the N content in the manure, which changed in each period of application (Table 1). Positive and linear response to PS has been reported for natural pastures (Scheffer-Basso et al, 2008), Tifton 85 (Vielmo et al, 2011) and giant missionary grass (A. jesuiticus x A. scoparius) (Miranda et al, 2012). These reports and our results indicate 150 m 3 PS ha -1 (499 kg N ha -1 ) did not differ from the DMY obtained with ammonium sulfate (60 kg N ha -1 ).…”

“…These reports and our results indicate 150 m 3 PS ha -1 (499 kg N ha -1 ) did not differ from the DMY obtained with ammonium sulfate (60 kg N ha -1 ). Miranda et al (2012), in the same experimental area where the present study was carried out, found that the effect of 165 m 3 PS ha -1 year -1 , or 300 kg N ha -1 year -1 , on the DMY of giant missionary grass, was similar to that obtained with 200 kg N ha -1 year -1 in the form of AN (625 kg ha -1 year -1 ), indicating the lower efficiency of PS in N supply compared with the AN. In the second year ( Figure 2B), the DMY increase was higher (average of 60%).…”

“…Plant response to N application varies with soil moisture, and higher response for grasses fertilized with N can be expected, since the soil moisture content is adequate (Sun et al, 2008). Miranda et al (2012) Table 2) can be assumed as high, since the carpet grass is a native species and was never subjected to any process of breeding.…”

“…In our work, the maximum DMY increase . In giant missionary grass, Miranda et al (2012) observed 321% increase of DMY in response to application of 275 m 3 PS ha -1 year -1 . In the first year (Figure 2A) of this study, there was no difference between the three higher doses of PS and AN, but in the following year, the yield with the highest PS dose exceeded that obtained with AN (Table 2).…”