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Soils under intensive and successive cropping with central pivot irrigation tend to present high nutrient contents, especially phosphorus (P), which is a nutrient with a great impact on the yield and quality of agricultural products. Among the rotating crops, the application of high P rates is common in processing tomato, although not supported by research. This work evaluates the effect of phosphate fertilization (0, 200, 400, 600, 800, and 1000 kg ha-1 P2O5) on the yield and quality of industrial tomato ‘Heinz 9553’ grown in a soil with high available P content (145 mg dm-3) resulting of an intensive vegetables cultivation, which have high demand by P. The highest total (127.4 t ha-1) and commercial (108.6 t ha-1) yields were obtained with 413.9 and 384 kg ha-1 P2O5, respectively. The results showed that pH of tomato juice, the percentages of green, red, and commercial fruits were not influenced by the applied P rates. However, nutrient delivery increased the soluble solids content up to 356 kg ha-1 P2O5, which is interesting for tomato processing. After harvesting the fruits, the available soil P content was increased with P supply to the plants. For improvement of commercial yield and soluble solids characteristics, the tomato crop shall be fertilised with P even though the soil has high P content.

An experiment was carried out in the city of Itápolis (SP), from October 2007 to January 2008, in a Red-Yellow Distrophic Argissolo (loamy soil), in order to evaluate growth, accumulation and exportation of macro and micronutrients in Top Gun hybrid watermelon. The experimental design took place in randomized blocks, having six different treatments corresponding to the sampling stages of plants: elongation of the main branch; presence of tertiary branches; early flowering; fruit with a diameter of 8 cm; fruit with a mass of between 4 and 5kg; and end of the cycle. The accumulation of dry mass was slow up to 35 DAS, increasing from this point on, reaching 1528 g plant -1 at the end of the cycle. The total accumulated dry mass was made up of 11.6% stems, 19.5% leaves, and 68.9% fruit. In terms of nutrient accumulation, this was also slow up to 35 DAS. With fruiting, came an increase in the demand for nutrients with 45 to 59 DAS being the period of greater nutritional demand. The order of decreasing nutrients was: K> N> Ca> Mg> P> S> Mn> Fe> B> Zn> Cu. The export of macronutrients (in kg ha -1 ) was 36.

Nitrogen is the second nutrient most demanded by arugula. However, the positive effect it has on yield can negatively impact the quality of this vegetable, with negative effects on human health. Two experiments (summer and autumn) were carried out to evaluate the effect of N rates (0, 50, 100, 150, 200 and 250 kg ha−1) on the arugula growth, yield and quality (nitrate content). Each experiment was set up in a randomized block design with four replications. Increasing rates of N reflected positively on leaf N content and thus, higher and desirable values of height, leaf number, leaf area and plant dry mass were obtained in both growing seasons. Consequently, the yield had significant increase, which N was maximized in summer (4.9 kg m−2) and autumn (2.6 kg m−2) and leaf N of 29.4 and 27.0 g kg−1, respectively, at rates of 250 and 213 kg ha−1 and both growing seasons. The higher rate the higher foliar nitrate content of arugula, in summer (2931.3 mg kg−1) and autumn (4218.4 mg kg−1). The foliar nitrate content in both crop season do not reach the risk level to human being heath.

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