Sources and doses of nitrogen in the production of sunflower plants irrigated with saline water

Abstract

The cultivation of sunflower allows its use as bio-fuel and alternative forage. It is a viable alternative in the semiarid regions. Current study evaluates the effect of saline water use, sources and doses of nitrogen fertilization on the production of sunflower in the experiment conducted in drainage lysimeters between May and August 2012, under protected conditions, at Pombal - PB Brazil. The experiment consisted of a randomized block design, with a 2 x 3 x 4 factorial arrangement and three replications. The treatments consisted of two levels of electrical conductivity of water - ECw (0.3 and 3.0 dS m-1), three sources of nitrogen (urea, ammonium sulfate and calcium nitrate) and four levels of N (40, 80, 120 and 160% of recommended dose - 100 mg kg-1, for trials in pots). Dry mass of chapter (DMC), mass of achenes (MAc), the number of viable seeds (MVS), total number of seeds (TNS) and internal (DCI) and external (DCE) diameter of chapter. Irrigation with water of ECw=3.0 dS m-1 negatively affected all variable evaluated. Doses of N 104 and 160% of recommended dose for trials in pots, resulted in the highest DMC, TNS, DCE and DCI. N sources and the interaction between factors did not affect significantly any of the variable evaluated.

Using water hyacinth (Eichhornia crassipes) biomass and humic substances to produce urea-based multi-coated slow release fertilizer

“…The nitrogen content of FERT was approximately 20%, indicating its potential for large-scale application, since the content was similar to that of commercial ammonium sulfate ((NH 4 ) 2 SO 4 , with 21% N and 24% S), one of the main sources of nitrogen used in global agriculture (Barbosa Filho et al 2004). However, different to (NH 4 ) 2 SO 4 , the fertilizer produced in this work could release nutrients slowly, reducing losses, the costs associated with reapplications, and environmental problems such as soil acidification, leaching, volatilization, and release of greenhouse gases (Ku et al 2017).…”

Sunflower performance as a function of phosphate fertilization in semiarid conditions

“…In the 2017 harvest, due to the high amount of rainfall that occurred during planting and in the initial phase of development (Figure 1), where it coincided with nitrogen fertilization, there was probably a great loss of the nitrogen applied through leaching, which resulted in a reduction in the availability of this nutrient for cultivation. The loss of nitrogen would have also caused smaller plants to develop since a low availability of N causes nutritional and physiological disturbances and reduces the production of achenes and the percentage of oil (Nobre et al, 2014). According to (Sanchez, 2007), the response of sunflower to phosphate fertilization is mainly related to P availability in the soil.…”

Water for irrigation at the Antônio Conselheiro settlement, Mato Grosso, Brazil

“…Besides soil salinization, the use of waters with high EC may negatively interfere with the development of several crops, since the presence of salts in the soil matrix changes osmotic balance, thus influencing their absorption (Nobre, et al, 2014;Oliveira, et al, 2014;Silva, et al, 2014). In this sense, the low electric conductivity values observed in both surface water and groundwater sources in the AAC area indicate that there is no risk of soil salinization in both periods.…”