Herbage yield and crude protein concentration of rangeland and pasture following hog manure application in southeastern Alberta

Abstract

Blonski, L. J., Bork, E. W. and Blenis, P. V. 2004. Herbage yield and crude protein concentration of rangeland and pasture following hog manure application in southeastern Alberta. Can. J. Plant Sci. 84: [773][774][775][776][777][778][779][780][781][782][783]. Intensive hog production is expanding into semi-arid regions of Alberta, where perennial forage lands are increasingly targeted for manure application despite limited guidelines for its efficient use. Herbage yield and crude protein were assessed over two consecutive years within two native rangelands and two tame pastures, following different rates (10, 20, 40, 80 and 160 kg ha -1 NH 4 -N), methods (surface banding vs. subsurface injection) and seasons (fall vs. spring) of one-time liquid hog manure (LHM) application. Increasing manure rates improved grass yield across all sites the first growing season after treatment, from 1626 to 3576 kg ha -1 . Although absolute increases in production were greatest on tame pasture, relative yield increases were similar among sites. Average crude protein (CP) concentration also increased from 69 to 91 g kg -1 in the first year. Despite low rainfall and the absence of a yield response in the second year, grass CP and crude protein yield (CPY) were maximized with increased manure application, highlighting the positive effects of manure on forage production, even with drought. Forb yields demonstrated variable effects among sites, with increasing manure decreasing alfalfa and increasing native forbs. Overall, both semi-arid tame pastures and native rangelands responded positively to LHM application, highlighting the complementary nature of hog and forage production under these conditions. Le rendement fourrager augmente avec le taux d'application à tous les endroits la saison végétative suivant le traitement pour passer de 1 626 à 3 576 kg par hectare. Bien que la production augmente davantage dans les prairies artificielles en termes absolus, le rendement relatif demeure le même aux différents endroits. La quantité moyenne de protéines brutes s'accroît elle aussi la première année, soit de 69 à 91 g kg -1 . Malgré la pluie et l'absence de réaction du rendement la deuxième année, la concentration de protéines brutes des herbages et le rendement en protéines brutes atteignent leur maximum avec l'augmentation du taux d'application, ce qui souligne les effets positifs du fumier pour la production fourragère, même quand il y a sécheresse. Le rendement en herbacées dicotylédones révèle que la réaction varie d'un site à l'autre, la production de luzerne diminuant et celle d'herbacées dicotylédones indigènes augmentant avec l'application de fumier. Dans l'ensemble, les prairies artificielles et les grands parcours naturels des régions semi-arides réagissent bien à l'application de lisier, signe que l'élevage de porc et la culture fourragère sont complémentaires dans de telles conditions.

Soil mineral nitrogen responses following liquid hog manure application to semiarid forage lands

“…Finally, changes in total soil mineral N (i.e., N depletion) from 1999 to 2000 were correlated with N removed in herbage biomass during the interceding growing season [see Blonski et al (2004) for detailed responses on N removal]. This assessment was done separately for each study site, with all available soil N depletion values converted to kilograms per hectare using mean bulk densities for each site and soil depth layer.…”

“…Each site was internally uniform with respect to physical conditions (e.g., slope, aspect, and topographic position) and initial vegetation, and established on vegetation in good to excellent condition. Each site measured 150 by 35 m and was fenced after treatment to exclude livestock to avoid confounding vegetation responses and manure treatments, with grazing permitted in late summer to avoid excess litter accumulation (Blonski et al 2004).…”

“…Ground samples were tested for plant N concentration using a LECO FP-428 nitrogen determinator (Lee et al 1996). Total N removed in each plot was derived by the determination of total herbage N yield, assessed as the sum of the products of total biomass (kg ha (1 ) and the specific concentration of N for each growth form (see Blonski et al 2004).…”

“…Final manure application volumes, adjusted for N concentrations, led to minimal variation in actual N rates between seasons, which ranged from 9.4 to 150 kg ha (1 N. Given that the 10 kg ha (1 rate could not be obtained under normal operating conditions due to an excessive machine speed requirement, this rate was achieved by diluting manure with water in a 1:1 mix. Thus, manure application volumes across treatments ranged from 13 000 to 107 000 L ha (1 in the fall, and from 11 000 to 84 000 L ha (1 in the spring (Blonski et al 2004).…”

“…Although potentially less productive, perennial forage lands, including native grasslands and introduced pastures, are often widely available adjacent to these operations and could provide an alternative sink for LHM disposal. Moreover, manure application can benefit forage crops through increased production and forage quality (Gangbazo et al 1999;Blonski et al 2004).…”