The influence of surface and sub‐surface application methods for pig slurry on herbage yields and nitrogen recovery

Abstract

Experiments were conducted on a grassland site at Wrest Park, Silsoe, Bedfordshire between 1987 and 1989, to compare herbage yields from slurry applied by deep and shallow injection, low trajectory and conventional vacuum tanker methods. Slurry application rates for all spreaders were calibrated at 86 ± 5 t ha~^, an equivalent of c, 200 kg NH4+-N ha-' applied in autumn or in spring.As expected, herbage yields following spring applications were higher than from autumn applications, with average mineral fertilizer equivalents of 122 and 89 kg N ha-i respectively. Yields from the conventional and low trajectory spreaders showed no consistent differences. However, in both years, first cut yields from plots were significantly lower (P < 0-05) where slurry had been injected than where surface applications had been used by an average of 0-7 t DM ha-i. Subsequent cuts in 1988 demonstrated higher residual effects from injection so that annual total yields were similar from all slurry applications irrespective of spreader type.Analysis of N content revealed high N levels in herbage from deep injection plots. Mean concentrations of N in the herbage, expressed as a percentage of the dry matter, were 1-43 for surface treatments and 1-79 for deep injection in I Present address and correspondence: Water Research Centre,

A survey of the production and use of animal manures in England and Wales. III. Cattle manures

“…Increased slurry storage capacity might be expected to confer improved flexibility and better timing for land spreading operations, with increased opportunity for slurry application in the spring to grassland or growing cereal crops (Rees et al 1993;Jackson & Smith 1997). There is some evidence of a trend for increased slurry application during the February to April period, on dairy and beef farms, where there is 3^6 months storage capacity (Figures 4 a & b).…”

A survey of the production and use of animal manures in England and Wales. I. Pig manure

“…Emissions from livestock production are much in¯uenced by management of the manure. For example, in mixed farming, it is common practice for livestock manures to be applied to arable land or grassland in the autumnwinter period, when the utilization of manure N is known to be generally poor (Rees et al 1993;Chambers et al 1994).…”

Surface‐Banding Liquid Manure over Aeration Slots: A New Low‐Disturbance Method for Reducing Ammonia Emissions and Improving Yield of Perennial Grasses

“…The amount of manure ammonia lost to the atmosphere is negatively related to rate of infiltration of manure into the soil; infiltration is enhanced by injection or incorporation of manure (Sommer and Hutchings, 2001). However, despite conserving ammonia, injection of manure may reduce yield of perennial grasses (Rees et al, 1993; Tunney and Molloy, 1986; Prins and Snijders, 1987). The yield reductions are attributed to the cutting of roots during injection (Rees et al, 1993), drying of the soil (Prins and Snijders, 1987), and anaerobic and toxic conditions from concentrating the manure in the injection slots (Tunney and Molloy, 1986).…”

“…However, despite conserving ammonia, injection of manure may reduce yield of perennial grasses (Rees et al, 1993; Tunney and Molloy, 1986; Prins and Snijders, 1987). The yield reductions are attributed to the cutting of roots during injection (Rees et al, 1993), drying of the soil (Prins and Snijders, 1987), and anaerobic and toxic conditions from concentrating the manure in the injection slots (Tunney and Molloy, 1986). The yield reduction is greater with multiple applications over the season (Prins and Snijders, 1987).…”