Frequency of defoliation and nitrogen and phosphorus fertilization onAndropogon gayanusKunth. II. Macroelement concentrations

Autor: Jesus Faria-Marmol, Lee Russell McDowell, Alfedo Caraballo, David E. Morillo
Rok vydání: 1997
Předmět:
Zdroj: Communications in Soil Science and Plant Analysis. 28:833-840
ISSN: 1532-2416
0010-3624
DOI: 10.1080/00103629709369834
Popis: An experiment was conducted in a semi‐arid region located in the State of Zulia, western part of Venezuela (10°32'N and 71°42'W, and 600 mm average annual rainfall), to evaluate ash and macroelement concentrations of Andropogon gayanus Kunth as affected by two frequencies of defoliation (every 42 and 63 days) and fertilization with three levels of nitrogen (N) (0, 100, and 200 kg N ha‐1‐year‐1) and two levels of phosphorus (P) (0 and 75 kg P2O5 ha‐1#lbyear‐1) in a factorial array using a split‐split‐plot experimental design with frequencies in the main plots, N in the sub‐plots, P in the sub‐sub‐plots, and two replications. Soil was a sandy‐loam Andisol with pH 5.5. Average soil calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), and P contents were 0.6, 0.3, 0.1, and 0.17 meq#lb100 g‐1 soil and 6 ppm, respectively. Data from six and four cuttings for the frequencies of 42 and 63 days were analyzed over the total duration of the study (252 days) as well as separately for periods with “high”...
Databáze: OpenAIRE