Effects of short‐term nitrogen supply from livestock manures and cover crops on silage maize production and nitrate leaching

Abstract

Resource use efficiency requires a correct appreciation of the nitrogen (N) fertilizer replacement value (NFRV, percentage of total N applied) of manures. We assessed the NFRVs of the liquid fraction originating from separated pig slurry (MC), untreated pig slurry (PS), untreated cattle slurry (CS), the solid fraction from separated pig slurry (SF) and solid farmyard manure from cattle (FYM) in two consecutive years in silage maize grown on a sandy soil. Maize yields responded positively to each of these N sources applied at rates up to 150 kg of mineral fertilizer equivalents per ha per year (i.e. NFRV 9 total N rate). The observed NFRVs, relative to calcium ammonium nitrate fertilizer, amounted to 78% for MC, 82% for PS, 79% for CS, 56% for SF and 34% for FYM when averaged over both years. NFRVs were positively related to the ammonium-N share in the total N content. Rye cover crop establishment after the harvest of maize reduced nitrate concentrations of the upper groundwater by, on average, 7.5 mg nitrate-N/L in the first year and 10.9 mg/L in the second year, relative to a bare soil. Regardless of the presence of a cover crop, nitrate concentrations responded positively to the applied rate of effective N (total N 9 NFRV) but less to postharvest residual soil mineral N.

Nitrogen Fertiliser Value of Digested Dairy Cow Slurry, its Liquid and Solid Fractions, and of Dairy Cow Slurry

“…Schröder et al (2007) reported ANRNH4-N values for two injected cattle slurries applied to cut grassland in the range of 62-76%, which is comparable to the 63-70% for the mineral fertiliser (calcium ammonium nitrate) obtained in the same trial. Another field experiment by Schröder et al (2013) resulted in higher ammonium ANRs compared to our experiment; they reported a firstyear ANRNH4-N of 58% for both injected cattle slurry and mineral fertiliser applied to silage maize. The high ammonium recoveries obtained by Schröder et al (2007Schröder et al ( , 2013 can be ascribed to the relatively lower range (15-16) of C to organic N ratio for the cattle slurry used in those field experiments -and thus to a lower N immobilisation -as compared to those of raw slurry used in our trial (20)(21)(22)(23)(24).…”

“…If our hypothesis proves true, then the first-year ANR of slurry can be calculated by multiplying its NH4-N/total N ratio and the ANR of the inorganic fertiliser, specific to site and application time. While this hypothesis appears reasonable for raw slurries (Sørensen et al, 2003;Schröder et al, 2005;Reijs et al, 2007;Schröder et al, 2013), studies of digested slurries and their fractions (Schröder et al, 2007;Chantigny et al, 2008;de Boer, 2008;Möller et al, 2008;Saunders et al, 2012;Sieling et al, 2013) are still rather scarce and insufficient to confirm it. Therefore, the two-year field experiment described in this paper, named SINBION-Field, included three objectives: i) to measure the ANR and MFE of raw, digested, and separated dairy cow slurries; ii) to verify the hypothesis that recovery of applied ammonium is similar among different slurries in the short term; iii) to verify the hypothesis that the recovery of applied ammonium is similar for slurries and inorganic N fertiliser (ammonium sulphate).…”

Nitrate leaching from liquid cattle manure compared to synthetic fertilizer applied to grassland or silage maize in the Netherlands

“…In their 4-year field experiment, Wachendorf et al ). It is unclear why the average NFRV of LCM (79%) was higher than usual (60%) (Schröder et al 2013), but a higher nitrate leaching loss from CAN due to drought on this sandy soil could have been the cause, similar to the mechanism suggested for grassland. High rainfall directly after CAN application could also have contributed to the difference in leaching between CAN and LCM.…”

Effecten van het mestbeleid op landbouw en milieu : Beantwoording van de ec-postvragen in het kader van de evaluatie van de meststoffenwet

“…• Na snijmaïs is het verplicht om een vanggewas te telen vanaf 2006, omdat een geslaagde teelt van een vanggewas leidt tot een lagere nitraatuitspoeling (Schröder et al, 2013).…”