Effect of fertilizers and planting methods on safflower fatty acid profile1

ABSTRACT Soils in semi-dry areas lack sufficient nutrients for crops, so their yield depends on fertilizers and planting methods. This study aimed to investigate how the fatty acids in safflower oil change with the use of fertilizers and planting methods. Five fertilizers [F1: control; F2: 10 t ha-1 of farmyard manure; F3: 20 t ha-1 of farmyard manure; F4: NPK (130:60:45 kg ha-1); F5: nano-Fe and nano-Zn] and four planting patterns (P1: 40-cm furrow planting; P2: 60-cm furrow planting; P3: 40-cm ridge planting; P4: 60-cm ridge planting) were tested. A biplot analysis explained 73 % of the variability, with the first and second principal components accounting for 54 and 19 %, respectively. The polygon-view was divided into five sections, with F3-P4 being the best for oil and protein contents, stearic (18:0), oleic (18:1), linoleic (18:2), linolenic (18:3) and lauric (12:0) acids, and iodine value. The vector-view showed a positive association among iodine value, oil content and linoleic, oleic, linolenic, stearic and lauric acids, as well as between myristic acid (14:0) and protein content, and between saponification and peroxide values. The best treatments were F4-P4, F4-P3 and F5-P4. Therefore, using NPK chemical fertilizer or nano-Fe and nano-Zn, combined with planting on a ridge with a 40 or 60-cm interrow distance, can be beneficial for producing high-quality safflower oil. RESUMO Solos em zonas semiáridas não proporcionam nutrientes suficientes para as culturas, tornando a produtividade delas dependente de fertilizantes e métodos de plantio. Objetivou-se investigar como os ácidos graxos do óleo de cártamo mudam com o uso de fertilizantes e métodos de plantio. Foram testados cinco fertilizantes [F1: controle; F2: 10 t ha-1 de esterco bovino; F3: 20 t ha-1 de esterco bovino; F4: NPK (130:60:45 kg ha-1); F5: nano-Fe e nano-Zn] e quatro padrões de plantio [P1: plantio em sulco de 40 cm; P2: plantio em sulco de 60 cm; P3: plantio em canteiro de 40 cm; P4: plantio em canteiro de 60 cm]. Um tratamento biplot explicou 73 % da variabilidade, com o primeiro e o segundo componentes principais representando 54 e 19 %, respectivamente. A perspectiva poligonal foi dividida em cinco seções, sendo F3-P4 a melhor para teores de óleo e proteína, ácidos esteárico (18:0), oleico (18:1), linoleico (18:2), linolênico (18:3) e láurico (12:0) e valor de iodo. A perspectiva vetorial mostrou associação positiva entre valor de iodo, teor de óleo e ácidos linoleico, oleico, lino