Leaching Losses Of Nutrients Research Articles

Differential leaching of nutrients from soluble vs. controlled-release fertilizers

Extremely sandy soils and poorly distributed high annual rainfall in the state of Florida contribute to significant leaching losses of nutrients from routine fertilization practices. A leaching column experiment was conducted to evaluate the leaching losses of nutrients when using currently available N, P, K blend fertilizers for young citrus tree fertilization. Fertilizer blends included NH4NO3, Ca(NO3)2, IBDU, IBDU plus Escote, Nutralene, Osmocote, and Meister. Following leaching of 1000 ml of water through soil columns, which simulates leaching conditions with 26 cm of rainfall, the amount of NO3 and NH4 recovered in the leachate from soil columns amended with an NH4NO3 blend accounted for 37% and 88% of the respective nutrients contained in the quantity of blend per column. The corresponding values for soil columns amended with a Ca(NO3)2 blend were 48% and 100%. Leraching losses of both NO3 (<3%) and NH4 (<4%) were drastically decreased when using controlled-release fertilizers. The recoveries of P and K in 1000 ml of leachate were 1.3% and 8%, respectively, of the nutrients added as Osmocote, which contained coated P and K sources. In the case of the rest of fertilizer blends, the recoveries of P and K in 1000 ml of leachate were as high as 52%–100% and 28%–100%, respectively. Therefore, controlled-release technology offers an important capability for minimizing leaching losses of nutrients.

Differences in the Quality of Food Eaten by Red Deer (Cervus elaphus) Stags and Hinds in Winter

An in situ field experiment with lysimeter was conducted to study the effects of different fertilizations on the nutrient leaching loss from brown soil in the growth season of summer maize. The results showed that abundant rainfall and irrigation were the main factors affecting the leaching loss. The leaching amount was higher in the early growth period of summer maize, but decreased after then. The difference among different fertilization treatments also decreased with maize growth. Comparing with N fertilization, wheat stalk plus N application intensified the leaching. During the growth period of summer maize, the NO3- -N content in leached water in fertilization treatments had two peaks, while the NH4+ -N content had a trend of increased first and decreased then. The leaching loss of soil N was mainly in the form of NO3- -N. The accumulative leaching loss of NO3- -N was 12.90-46.53 kg * hm(-2), and that of NH4+ -N was 1.66-5.11 kg x hm(-2), both of which increased with increasing N application rate. The leaching rate of soil N was 6.53%-13.07% higher in treatment wheat stalk plus N application than in treatments of N fertilization, and 3.66%-10.10% higher in low N treatments than in high N treatments. The accumulative leaching loss of available P was only 0.148-0.235 kg x hm(-2), while that of available K was 7.08-13.00 kg x hm(-2). In the late growth period of summer maize, wheat stalk plus N application increased the leaching loss of soil available P and K, while nitrogen application affected it slightly.

Relations between nutrient concentrations in plant tissues and responses of white clover to fertilisers on a gley podzol near westport

Abstract Nutrient concentrations in plant tissues were related to yield responses in three fertiliser experiments on virgin Addison sandy loam. Yield responses indicated initial requirements for vigorous growth of white clover of at least 30 cwt agricultural limestone per acre, phosphate equivalent to 9 to 12 cwt superphosphate, 3 to 4 cwt potassium chloride, about 20 lb elemental sulphur, 5 lb each of copper and zinc sulphates, and 1 oz sodium molybdate. Indicated maintenance needs were about 5 cwt limestone per acre per annum, 6 cwt superphosphate, 3 to 4 cwt potassium chloride, and 20 lb elemental sulphur. The low retentive capacity of this soil for phosphate, sulphate, potassium, and calcium, combined with a mean annual rainfall of about 100 in., led to rapid leaching losses of nutrients and therefore abnormally high maintenance needs. Associated with yield responses, N concentrations in white clover leaves (blades plus petiole) increased with increasing rates of mono-calcium phosphate, lime, sulphur,...