We studied the effects of five thinning treatments (T1 = 5.5, T2 = 11, T3 = 16.5, T4 = 22.5 and T5 = 28.5 m(2) ha(-1) basal area under bark) x two fertilizer treatments (F0 = unfertilized and F1 = fertilized with 400 kg ha(-1) N plus 229 kg ha(-1) P) on growth and water relations of pole-sized Eucalyptus marginata J. Donn ex Sm. trees growing in southwestern Australia. Thinning reduced leaf are...

A field study was conducted on hummocky terrain at the Manitoba Zero Tillage Association Research Farm near Brandon, Manitoba, Canada to determine the variability of crop yield as related to landscape position, soil properties, weed populations and plant disease. This information was used to develop a method for delineation of management units related to precision farming. Variable-rate fertili...

Nitrogen utilization by corn (Zea mays L.) is influenced by the form of inorganic N present in the root zone. A field experiment was conducted on Enon sandy loam (fine, mixed, thermic Ultic Hapludalf) to determine N use efficiency and its partitioning in various plant parts of corn. Ammonium nitrate labeled either as NH4-N or NO3-N and applied at 50, 100, or 200 kg N ha" was evaluated. Microplo...

In order to study of the effect of seed inoculation with PGPR on nitrogen and phosphorus use efficiency of spring wheat in different levels of nitrogen and phosphorus fertilizers, an experimental was conducted at the Research Farm of Mohageh Ardabili University, Ardabil, Iran during 2012 year. The combination of nitrogen fertilizer in three levels (0, 40 and 80 kg N/ha as urea) and phosphorus f...

Investigations were carried out to study the effect of organic farming with various sources of organic manures and their combinations on nitrogen use efficiency parameters of ADT 36 rice (Oryza sativa L.). The experiments were laid out in randomized block design (RBD) with fourteen treatments, comprising twelve treatment combinations of organic manures, one treatment with recommended dose of ch...

In dairy production systems, tradeoffs can occur between fertilizer N applications and crop N use, feed N consumption and manure N excretion, and environmental impacts. This paper examines (i) how stocking rates affect N imports and management on dairy farms, N use efficiency (NUE; i.e., the amount of applied N incorporated into product N), and N loss; (ii) how reductions in fertilizer N and fe...

abstract- declining land productivity associated with decreasing soil organic carbon and nutrients is a significant issue in monoculture production. the field experiment with different rates of fertilizer systems (60 kg ha-1 n + 100 kg ha-1 p, 300 kg ha-1 bio-organic (organic fertilizer), 3 kg ha-1 bioumik (biofertilizer), 30 kg ha-1  n + 50 kg ha-1 p + 150 kg ha-1 bio-organic fertilizer and 30...

Differences in 3 response among corn (Zea mays L.) genotypes reflect variation in numerous processes involved in N use efficiency. In order to facilitate the study of such variation, we develop and demonstrate a concept for evaluating the contribution of N uptake and utilization processes to variation in N use efficiency. Eight hybrids were grown in a replicated field experiment at two levels o...

The use of the 15N label for agronomic research involving nitrogen (N) cycling and the fate of fertilizer-N is well established, however, in the case of long term experimentation with perennial crops like citrus, coffee and rubber tree, there are still shortcomings mainly due to large plant size, sampling procedures, detection levels and interferences on the system. This report tries to contrib...