GÜLLE AS A GRASSLAND FERTILIZER (PART III)

Results from current trials indicate that soil type, time of application and weather influence responses to applications of gulle. Over 3 sites gulle N had an efficiency of about 60% of that of fertilizer N. Best results were obtained from heavy clay soils or those containing much organic matter. Winter applications of dilute gulle to light soils under wet conditions may result in large losses of N through leaching. Generally, winter gulle applications may lead to severe losses of plants in short‐term ryegrasses with associated heavy uptakes of K in spring. It is concluded that much of the gulle produced should be broadcast in winter on to swards destined for mowing in early summer. Optimum utilization of gulle calls for supplementation with fertilizer N, when the full potential of the K derived from the sludge can be exploited.