Clementino Marcos Batista de Faria

Adubação verde com leguminosas em videira no submédio São Francisco

SUMMARY : GREEN MANURING GRAPEVINE WITH LEGUMES IN THESUBMIDDLE SAO FRANCISCO RIVER VALLEY The soils of the Submiddle Sao Francisco River Valley are generally sandy, with lownutrient retention capacity. Since they are located in a semi-arid area, they are very poor inorganic matter (OM) and as a consequence are deficient in nitrogen, which limits agriculturalproduction. Thus, the use of legumes as green manure may overcome this problem becauseit adds carbon and nitrogen to soil. The study comprised two experiments with legumesintercropped with irrigated grape ( Vitis vinifera ) in a sandy Ultisol in Petrolina, State ofPernambuco (Brazil) from June 1996 to July 2002. The objective was to evaluate the effectsof green manure on soil chemical characteristics and on grape yield and quality. The firstexperiment lasted until the fourth grape harvest. The treatments consisted of two legumes:sunnhemp ( Crotalaria juncea ) and jack bean ( Canavalia ensiformis ), submitted to twomanagements (sub-plot): (a) cut and left on the soil surface and (b) cut and incorporatedinto the soil. There was a control treatment (without green manure). In the second experiment,which began in the fifth grape production cycle, the methodology consisted of three treatments:(1) control; (2) sunnhemp and (3) jackbean combined with two subplot treatments: (a) 100 %of the fertilizer recommended by soil analysis, and (b) 50 % of the recommended fertilizer.Altogether, there were eleven legume cycles and nine harvests of table grape. The biomassproduction of the legumes decreased over time. Green manure improved the soil chemicalcharacteristics, increasing OM and exchangeable Ca content, and the CEC value in the0–10 cm soil layer. There was no consistent effect of the green manure on the yield andquality of table grape.Index terms:

Níveis de nitrogênio por fertirrigação e densidade de plantio na cultura do melão em um Vertissolo

O trabalho constou de um experimento com melao (Cucumis melo L.), conduzido em um Vertissolo, em Juazeiro, BA, em 1995, com o objetivo de avaliar o efeito de niveis de N por fertirrigacao e de densidades de plantio na produtividade e qualidade de fruto. Os niveis de N foram 0, 80, 130 e 180 kg/ha, combinados com os espacamentos 2,00 e 1,80 m entre linhas e 0,20 m entre plantas, com uma ou duas plantas por cova. A fonte de N foi a ureia, aplicada diariamente ate 42 dias apos a germinacao, por meio da irrigacao por gotejamento. Todos os tratamentos receberam uma adubacao uniforme de 120 kg/ha de P2O5 e 120 kg/ha de K2 O. Os espacamentos entre linhas nao causaram diferencas significativas em nenhuma variavel estudada. O nivel de 80 kg/ha de N combinado com uma planta por cova proporcionou uma produtividade de 34,07 t/ha, com 55,7% de frutos proprios para o mercado interno, nao-significativamente (P £ 0,05) inferior a produtividade obtida com os niveis mais elevados de N em qualquer combinacao. Com este mesmo nivel, obtiveram-se frutos com 10,22o Brix significativamente (P£ 0,05) superior ao do tratamento sem N e nao-significativamente inferior ao dos outros niveis. Para se obter uma maior parte de frutos proprios para o mercado externo, foi necessario elevar a densidade para duas plantas por cova e o nivel de N para 130 ou 180 kg/ha. O peso medio dos frutos aumentou de 1,008 para 1,705 kg, a medida que foram aumentados os niveis de N ou se diminuiu a densidade de plantio de duas para uma planta por cova.This study consisted of one experiment with melon (Cucumis melo L.), carried out in a Vertisol in Juazeiro, BA, Brazil, in 1995, with the objective of evaluating the effects of nitrogen levels through fertirrigation and plant density on fruit yield and quality. The N levels were 0, 80, 130 and 180 kg/ha, combined with row spacings of 2.0 and 1.8 m and 0.20 m between plants within the row, with one or two plants/hole. The source of N was urea applied daily up to 42 days after germination, through drip irrigation. All treatments had a uniform fertilization of 120 kg/ha of P2O5 and 120 kg/ha of K2O. No significant difference was caused by spacing between rows in the studied variables. Eighty kg/ha of N combined with one plant per hole gave a yield of 34.07 ton/ha, being 55,7% of fruit allocated to inside market, not significantly lower than those obtained with the highest N levels in any combination. This same N level gave fruits with 10.22o Brix, significantly higher than the treatment without N and not significantly lower than the other levels. In order to get high number of good fruit for out side market it was necessary to elevate the density to two plants per hole and N level to 130 or 180 kg/ha. Mean weight of fruits increased from 1.008 to 1.705 kg with the increase in the levels of N and the decrease in plant density of two plants per hole to one plant per hole.

Fontes de fósforo aplicadas na cultura do melão via água de irrigação

This study was carried out with the objective of evaluating the effect of three phosphorus sources applied conventionally and through trickle irrigation on melon crop (Cucumis melo L.), hybrid AF-682. The sources of phosphorus were simple superphosphate, monoammonium phosphate (MAP) and phosphoric acid applied up to 30 and 42 days after germination through trickle irrigation and conventionally. The experiment was conducted in a completely randomized block design, with four replications. All the treatments had the same amount of phosphorus (120 kg ha-1 of P2O5) according to soil analysis. The highest commercial fruit yields were obtained with phosphoric acid applied through trickle irrigation up to 30 and 42 days after germination (28.90 and 32.20 t ha-1, respectively), not differing from MAP applied through trickle irrigation up to 42 days after germination (27.95 t ha-1). The sources of phosphorus and modes of application did not influence the mean weight of fruits (1.43 kg), 65% of fruits being of type 8 to 10; however differences were observed in the soluble solids content at harvest time, highest content (brix 12.53o) was obtained in phosphoric acid treatment.

Efeito de fertilizantes nitrogenados na produtividade de melão

A study was carried at Petrolina-PE, Brazil, with the melon crop (Cucumis melo L.), cv. Valenciano Amarelo, in a Red-Yellow Latosol with the objective of evaluating the effect of nitrogen fertilizers sources and their combinations, applied through the conventional way and through water irrigation during the crop cycle. The experimental design was a split block with four replica- tions and nine treatments: 1. control (without N); 2. urea; 3. ammonium sulphate, both applied con- ventionally; 4. urea applied up to 42 days after germination; 5. ammonium sulphate applied up to 42 days after germination; 6. urea applied up to 15 days and potassium nitrate from 16 to 42 days after germination; 7. urea applied up to 15 days and ammonium sulphate from 16 to 42 days; 8. urea applied up to 30 days and potassium nitrate from 31 to 42 days, and 9. urea applied up to 15 days, ammonium sulphate from 16 to 30 days and potassium nitrate from 31 to 42 days, at the level of 80 kg/ha of N. The fertilizers used during the crop cycle (treatments 4 to 9) were applied through irrigation water. It was found that urea applied through fertirrigation up to 42 days provided higher yield (31.14 ton/ha), not differing, however, from the other treatments, with the exception of the control and ammonium sul- phate, which gave the lowest yields (25.06 and 24.65 ton/ha, respectively). It was found a variation in fruit mean weight from 1.63 to 1.84 kg/fruit. There was no significant difference in total soluble solid content ( o Brix ) among the treatments.

Cultivo de melão orgânico: fosfatos naturais como fontes alternativas de fósforo

Aiming to evaluate the efficiency of natural phosphates in melon organic cropping under irrigation, two experiments were carried out in Petrolina-PE, one in a Yellow Argisol (PA) and other in a Grey Argisol (PAC). The evaluated treatments were: 1 - without P, 2 - 50 kg ha-1 of P2O5 as triple super phosphate (TS), 3 - 100 kg ha-1 of P2O5 as TS, 4 - 150 kg ha-1 of P2O5 as TS, 5 - 100 kg ha-1 of P2O5 as thermo phosphate, 6 - 100 kg ha-1 of P2O5 as natural phosphate of Gafsa and 7 - 100 kg ha-1 of P2O5 as natural phosphate Fosbahia. The melon crop showed similar responses to the P application in both soils, whose maximum productivities of 26.00 t ha-1 and 25.46 t ha-1 were obtained with 107.6 kg ha-1 and 118.6 kg ha-1 of P2O5 in PA and PAC, respectively. The efficiency of thermo phosphate, phosphate of Gafsa and Fosbahia in relation to TS assumed the sequence of 86.2%, 77.1% and 71.9% in PA and 101.5%, 72.3% and 67.3% in PAC. These results suggest that thermo phosphate is the most appropriated phosphate source to be used in the melon organic cropping. It is necessary 843.12 kg of thermo phosphate to produce 25 t ha-1 of melon fruit that represent 3.4% of the production cost.

Efeito de fosfatos naturais em plantas de melão cultivadas em vasos.

Organic agriculture is an emerging activity in the upper mid Sao Francisco River Valley, requiring technologies that are in line with the principles of this agricultural system. A study was carried out at Embrapa Semi-Arido to evaluate the efficacy of natural phosphates applied to three regional soils (dystrophic Grey Argisol - PAGd, eutrophic Yellow Argisol - PAe and Vertisol - V) planted with melon (Cucumis melo) in pots accommodated on wooden benches. The factorial treatments (3 x 4) + 1 consisted of three phosphorus levels (40, 80 and 160 mg dm-3 P2O5), four phosphorus sources (triple superphosphate-ST, thermophosphate-TM, Gafsa natural rock phosphate-FG and Fosbahia natural phosphate-FB) and a control treatment without phosphorus, in a completely randomized design with three replications. Each soil represented a trial. Shoot dry matter (DM), P plant content and P soil concentration extracted by Mehlich-1 and anionic exchange resin (AER) were evaluated 38 days after planting. In V and PAGd soils the phosphates were less effective than in PAe soil. TM was the P source with the highest efficiency for DM production in the three soils (56 to 100 % in relation to triple super phosphate). In PAe, FG also presented relatively high efficiency, equivalent to 80 % of that obtained with triple super phosphate. The Mehlich-1 and AER extractors were equally effective at evaluating P availability.

Nitrogen levels through fertirrigation and plant density on melon crop in a Vertisol

O trabalho constou de um experimento com melao (Cucumis melo L.), conduzido em um Vertissolo, em Juazeiro, BA, em 1995, com o objetivo de avaliar o efeito de niveis de N por fertirrigacao e de densidades de plantio na produtividade e qualidade de fruto. Os niveis de N foram 0, 80, 130 e 180 kg/ha, combinados com os espacamentos 2,00 e 1,80 m entre linhas e 0,20 m entre plantas, com uma ou duas plantas por cova. A fonte de N foi a ureia, aplicada diariamente ate 42 dias apos a germinacao, por meio da irrigacao por gotejamento. Todos os tratamentos receberam uma adubacao uniforme de 120 kg/ha de P2O5 e 120 kg/ha de K2 O. Os espacamentos entre linhas nao causaram diferencas significativas em nenhuma variavel estudada. O nivel de 80 kg/ha de N combinado com uma planta por cova proporcionou uma produtividade de 34,07 t/ha, com 55,7% de frutos proprios para o mercado interno, nao-significativamente (P £ 0,05) inferior a produtividade obtida com os niveis mais elevados de N em qualquer combinacao. Com este mesmo nivel, obtiveram-se frutos com 10,22o Brix significativamente (P£ 0,05) superior ao do tratamento sem N e nao-significativamente inferior ao dos outros niveis. Para se obter uma maior parte de frutos proprios para o mercado externo, foi necessario elevar a densidade para duas plantas por cova e o nivel de N para 130 ou 180 kg/ha. O peso medio dos frutos aumentou de 1,008 para 1,705 kg, a medida que foram aumentados os niveis de N ou se diminuiu a densidade de plantio de duas para uma planta por cova.This study consisted of one experiment with melon (Cucumis melo L.), carried out in a Vertisol in Juazeiro, BA, Brazil, in 1995, with the objective of evaluating the effects of nitrogen levels through fertirrigation and plant density on fruit yield and quality. The N levels were 0, 80, 130 and 180 kg/ha, combined with row spacings of 2.0 and 1.8 m and 0.20 m between plants within the row, with one or two plants/hole. The source of N was urea applied daily up to 42 days after germination, through drip irrigation. All treatments had a uniform fertilization of 120 kg/ha of P2O5 and 120 kg/ha of K2O. No significant difference was caused by spacing between rows in the studied variables. Eighty kg/ha of N combined with one plant per hole gave a yield of 34.07 ton/ha, being 55,7% of fruit allocated to inside market, not significantly lower than those obtained with the highest N levels in any combination. This same N level gave fruits with 10.22o Brix, significantly higher than the treatment without N and not significantly lower than the other levels. In order to get high number of good fruit for out side market it was necessary to elevate the density to two plants per hole and N level to 130 or 180 kg/ha. Mean weight of fruits increased from 1.008 to 1.705 kg with the increase in the levels of N and the decrease in plant density of two plants per hole to one plant per hole.

Ação de calcário e gesso sobre características químicas do solo e na produtividade e qualidade do tomate e melão

The influence of lime and gypsum on soil characteristics and on yield and quality of tomato and melon fruits was evaluated in two experiments, carried out in the same site in a sandy Red Yellow Argisol in the Submedio Sao Francisco River region. The experimental design was a randomized complete block with four replications and seven treatments: 1) control; 2) half of liming need (N.C.) as limestone (Cal.); 3) 1 x N.C. (Cal.); 4) 2 x N.C. (Cal.); 5) 0.5 x N.C. as 2/3 limestone and 1/3 gypsum (Cal.Ges.); 6) 1 x N.C. (Cal.Ges.); 7) 2 x N.C. (Cal.Ges.). Limestone and gypsum were applied in November 2000; the tomato crop was grown from May to August 2001 and the melon crop from September to November 2001. Liming and gypsum applications resulted in an improvement of pH and increased the levels of Ca2+and Mg2+ and reduced the amount of Al3+ in the soil, the effect being more evident on the increase of Ca2+ levels, up to 60%, and on the decrease of Al3+ levels, up to 68.7%. Limestone by itself was more efficient for neutralizing Al3+ at depth for melon crop than limestone associated with gypsum. The rate of 2.0 tons of limestone/ha (1 x N.C.) was enough to give a melon yield of 22.5 tons ha-1 and to reduce by 80.4% the incidence of the blossom end rot disease in tomatoes. Therefore, gypsum was not necessary for these crops.

Adubação fosfatada em tomateiro industrial em solos do Submédio São Francisco

Results of eight field experiments carried out in irrigated areas of the Submedio Sao Francisco River Valley, Northeast Brazil, from 1988 to 1993, were statistically analysed to evaluate the response of processing tomato (Lycopersicon esculentum, Mill) to phosphorus fertiliser, in soils with different available phosphorus contents by the methods of Mehlich - 1 or Bray - 1. The analysis showed that in soils where available P content was equal to or lower than 2 mg.dm-3, the mean increment in tomato yield due to P fertilisation was 190.8%, while in soils where the P content was 8 mg/dm3, the increment was only 21.7%. However, in soils with P content equal or higher than 14 mg dm-3, there was no response of the tomato crop to phosphorus fertilisation. In the two experiments where a quadratic response was observed, the maximum economical yields of 56.47 and 69.35 ton. ha-1 of tomatoes were obtained with 143 and 182 kg.ha-1 of P2O5, respectively.

Fontes e métodos de aplicação de fósforo na cultura do melão

This study was carried out at Petrolina, PE, Brazil, with the objective of evaluating the effect of two sources of phosphorus applied conventionally and through trickle water irrigation on melon (Cucumis melo L.), cv. Valenciano Amarelo. The experiment was run in a randomized complete blocks design, with four replications and five treatments: 1. simple superphosphate; 2. monoammonium phosphate (MAP) applied conventionally; 3. MAP applied through trickle water irrigation up to 15 days after germination; 4. MAP applied through trickle water irrigation up to 30 days after germination, and 5. MAP applied through trickle water irrigation up to 42 days after germination. All the treatments had the same amount of phosphorus (120 kg/ha of P2O5) according to soil analysis. The highest commercial fruit yields were obtained with MAP and simple superphosphate applied conventionally (27.42 and 25.96 ton/ha, respectively), not differing from MAP applied through trickle water irrigation up to 30 and 42 days after germination, but surpassing the yield of 19.47 ton/ha obtained with MAP applied through water irrigation up to 15 days after germination. It was found that the sources of phosphorus and ways of application did not influence on the mean weight of fruits (1.86 kg) and on the soluble solids content at harvest time, which varied from 12.75 to 13.17oBrix.