Comparison of initial wetting pattern, nutrient concentrations in soil solution and the fate of15N-labelled urine in sheep and cattle urine patch areas of pasture soil

Abstract

Three field experiments were carried out to compare cattle and sheep urine patches in relation to (i) initial wetting pattern and volume of soil affected, (ii) soil solution ionic composition and (iii) the fate of lSN-labelled urine in the soil over the winter period. The distribution of Br-(used as a urine tracer) across the soil surface and down the profile was irregular in all the patches. The pasture area covered by Br-in the sheep patches was 0.04-0.06 m 2 and Br-was detected to a depth of 150 mm. Cattle patches were significantly larger covering a surface area of 0.38-0.42 m 2 and penetrating to a depth of 400 mm. The rapid downward movement of urine occurred through macropore flow but even so, over half of the applied Br-was detected in the 0-50 mm soil layer in both sheep and cattle patches. Due to the larger volume of urine added to the cattle patches (2000 mL for cattle and 200 mL for sheep) the effective application rate was about 5 L m -2 compared with 4 L m -2 for sheep. Concentrations of extractable mineral N and ionic concentrations in soil solution were higher in cattle than sheep patches particularly near the soil surface. In both sheep and cattle patches, urea was rapidly hydrolysed to NH +. and nitrification occurred between 14 and 29 days after urine application. Initially the major anions and cations in the soil solution were HCO 3, SO 4, CI-, NH +, Mg ++, K + and Na +, which were derived from the urine application. Ionic concentrations in the soil solution decreased appreciably over time due to plant uptake and possibly some leaching. As nitrification proceeded, NO 3 became the dominant anion in soil solution and the major accompanying cation was Ca ++. The fate of tSN-labelled urine-urea was followed during a 5 month period beginning in late autumn. Greater leaching losses of NO 3 occurred below cattle patches (equivalent to 60 kg N ha-~ below 300 mm and 37 kg N ha-1 below 600 mm) compared with sheep patches (10 kg N ha -1 below 300 mm and 1 kg N ha -1 below 600 mm). While 6% of the applied 15N was leached the amount of N leached was equivalent to 11% of the applied urine-N in cattle patches. This suggests that there was significant immobilsation-mineralisation turnover in urine patch soil with the release of mineral N from native soil organic matter. In both sheep and cattle patches 60% of the 15N was accounted for in plant uptake, remaining in the soil and leaching. About 40% of the applied N was therefore lost through gaseous emission.

The fate of potassium, calcium, and magnesium in simulated urine patches on irrigated dairy pasture soil

“…However, pasture recoveries of urine applied K can be high, with recoveries of urine K over 8 and 20 month periods being reported at 40 and 20-23%, respectively (During & McNaught 1961;Williams et al 1989). Similarly, Williams & Haynes (1994) reported a 53% pasture recovery of urine K only 29 days after a urine application.…”

Fourfold Increase in Pumpkin Yield in Response to Low-Dosage Root Zone Application of Urine-Enhanced Biochar to a Fertile Tropical Soil

“…was mixed at a ratio of 1:5 with water to avoid cauterization, and then poured over the planting area of each treatment plot, except for a small seeding ring of 10 cm diameter in the middle of the planting area. As urine rapidly penetrates the soil to a depth of 40 cm [42], it was decided to apply the water-mixed urine on the top and not at the bottom of the planting pit to avoid a too rapid downward flow and leaching of the nutrients to deeper soil horizons, which would then be out of the reach of the pumpkin roots. For each plot of treatment B, 290 g (DM) of production fresh biochar (0.75 t·ha ), which corresponds roughly to a volume ratio of 1:1.…”

Disentangling the effect of sheep urine patch size and nitrogen loading rate on cumulative N2O emissions

“…The wetted area of a urine patch has been defined as the surface area covered by urine following deposition to soil, as opposed to the pasture response area, which can extend beyond the wetted area (Lantinga et al 1987;Li et al 2012). A typical wetted area for a sheep urine event with a volume of 150 mL is reported to be 300 cm 2 (Doak 1952) and for 200 mL it is reported to be 430-550 cm 2 (Williams and Haynes 1994). Typical urine applications of 4 L/m 2 were reported to be utilised in Kelliher et al (2014).…”