The effect of N applications (time and rates) on chlorophyll and N contents in bean leaves was evaluated and correlations among them and with the yield established. Carried out in the Selvíria region, State of Minas Gerais, Brazil, the experiment was set up in a completely randomized block design in a factorial 3 x 5 scheme. Treatments consisted in the combination of N (urea) application by side dressing at five levels (0, 35, 70, 105, and 140 kg ha-1 of N) at three times […]

Sugarcane (plant cane) yield and the N utilization of urea applied onto the cultivation was evaluated in a sandy soil with incorporated crop residues (roots, rhizomes, stalks, tops and dry leaves) in a pot experiment (220 L). The studied factors were: N doses (0, 30, 60 and 90 kg ha-1), applied as urea-N labeled with 15N and sugarcane crop residues incorporated in the soil, with and without dry leaves. The design of the experiment was of randomized blocks in three […]

This research aimed to evaluate the influence of nitrogen sources and application time on yield and quality of bean seed cropped in the winter period. A clayey typic Haplustox was used in a 2 x 7 factorial scheme, with 2 N sources (urea and ammonium sulfate) and 7 application time combinations (0-0, 0-75, 15-60, 30-45, 45-30, 60-15, and 75-0 kg ha-1 of N, respectively at sowing time and 22 days after plant emergence). Treatments were supplied 60 kg ha-1 P2O5 […]

An experiment was carried out at the Instituto Agronômico (SAA-SP) Experimental Station, in Piracicaba-SP, from March/94 to April/95, to evaluate the potential of velvet bean (Mucuna aterrima) green manure and urea, applied alone or combined, to supply nitrogen to corn crop. The experiment consisted of a preliminary phase for the production of velvet bean under field conditions and for the production of green manure labeled with 15N under greenhouse conditions. The green manure was later incorporated to the soil and […]

Urea and uan were side-dressed applied on the soil surface and incorporated (5-7 cm) to corn in a no-tillage system to study the balance of urea-N (15N) at harvest and measure the accumulated losses of NH3-N derived from these sources and from urea + KCl (solid) and uan + KCl (liquid), applied as 06-00-09 (N-P2O5-K2O) to the surface only. The treatments-originated from a factorial 1 + (2 x 2) + 2, with plot being + factorial 2 x 2 (two […]

A field experiment was carried out on a dark-red latosol (Oxisol) of the Centro de Pesquisas Novartis-Seeds, in Uberlândia, State of Minas Gerais, Brazil. The objective of this study was to evaluate the effects of irrigation, side-dressed application of urea, and urea partially substituted by ammonium sulphate on losses of NH3-N by volatilization in corn crop. The fertilizers were applied at 25 and 36 days after planting. The treatments, arranged in randomized complete block design, were: (i) control, (ii) urea, […]