The common bean succession to intercropped crops in the no-tillage system is beneficial, especially in the search for sustainability. In addition to the straw production, the intercropping can supply nitrogen (N) to the common bean grown in succession, reducing the use of mineral fertilizer, which is pollutant and has a high cost. The present study aimed to evaluate the response to N fertilization of common bean in succession to maize cropping systems, as well as the viability of these systems in the no-tillage system. The experimental design was randomized blocks, in a split-plot arrangement, with four replicates. The plots consisted of the following systems: maize as a single crop, maize intercropped with brachiaria and maize intercropped with crotalaria. The subplots were five N doses (0 kg ha-1, 50 kg ha-1, 100 kg ha-1, 150 kg ha-1 and 200 kg ha-1), applied as topdressing fertilization in winter common bean, in succession to the maize cropping systems. For the maize cultivation systems, the grain yield and N amount and accumulation in the straw were evaluated. As for the common bean in succession, the grain yield and grain quality attributes were assessed. Although the three cropping systems were viable for maize grain yield, the intercropping of maize with crotalaria led to a higher N accumulation in the straw and a larger quantity of straw dry mass. The increase of the N doses promoted an increase in the grain yield of common bean grown in succession to intercropped maize. Maize intercropped with crotalaria resulted in grains with a higher size and, concerning the grain yield, an equivalent effect to that of a topdressing application of more than 200 kg ha-1 of N was observed for the common bean in succession.

RESUMOUm dos métodos de manejo da irrigação mais utilizado é o tanque classe A, necessitando dos valores dos coeficientes de cultura para cálculo da evapotranspiração. O objetivo deste trabalho foi determinar os coeficientes de cultura (Kc) do tomateiro irrigado para a região de Uberaba, MG. Os dados do balanço de água no solo foram obtidos em uma área experimental com a cultura em tratamentos envolvendo níveis de reposição de água no solo (40%, 70%, 100%, 130%, 160% e 190% da lâmina necessária para elevar a umidade do solo para a condição equivalente à capacidade de campo). Os dados de tensão de água no solo foram coletados nas parcelas de 100% de reposição. A evapotranspiração de referência foi obtida pelo método do tanque classe A e a evapotranspiração da cultura por meio do balanço da água no solo. Concluiu-se que os valores de Kc para as fases inicial, desenvolvimento, intermediário, final e colheita foram, respectivamente, de 0,37; 0,72; 1,03; 1,10 e 0,75. UNITERMOS:Lycopersicon esculentum L., coeficiente de cultura, déficit hídrico. SANTANA, M.J.; PEREIRA, U.C.; BEIRIGO, J.D.C.; SOUZA, S.S.; CAMPOS, T.M.; VIEIRA, T.A. CROP COEFFICIENT FOR IRRIGATED TOMATO ABSTRACTOne of the most utilized irrigation management methods is the class A Pan, which requires crop coefficients to estimate crop evapotranspiration. The objective of this work was to determine crop coefficients (Kc) of irrigated tomato in the region of Uberaba, MG. Soil water balance data were obtained in an experimental area with the culture under six levels of soil water replacement (40%, 70%, 100%, 130%, 160% and 190% of the depth necessary to raise the soil moisture to the field capacity condition). The soil water tension data were collected in plots of 100% replacement. The reference evapotranspiration was obtained by the class A Pan method and culture evapotranspiration was obtained utilizing soil water balance. Kc values for the initial, development, intermediate, final, and harvest phases were respectively of 0.37; 0.72; 1.03; 1.10 and 0.75.

Intercropping maize (Zea mays L.) with cover crops (Crotalaria spectabilis and Urochloa ruziziensis) is a sustainable cultivation strategy that can generate ecological benefits combined with grain yield (GY). However, cover crops may require nitrogen (N) fertilization management to be adjusted to obtain a high GY in intercropping systems. This study was carried out over 2 years in southeastern Brazil using randomized complete block design in a split-plot scheme. The plots were composed of three cropping systems: sole maize, maize + U. ruziziensis and maize + C. spectabilis. The subplots consisted of four N levels: 0, 70, 140 and 210 kg/ha. The GY of the maize + U. ruziziensis may be reduced by 13% compared to the sole maize. The GY of the sole maize increased up to 11.3 Mg/ha for 95 kg/ha of N in the first year and 6.7 Mg/ha for 169 kg/ha of N in the second year. The GY of the maize + U. ruziziensis intercropping system showed linear increments of 120 kg/ha for every 10 kg/ha of N applied. In the maize + C. spectabilis intercropping, GY increased up to 9.8 Mg/ha for 201 kg/ha of N in the first year, without any variation during the second year. The land equivalent ratio (LER) of intercropping was increased by more than 35% compared to that of sole maize, and N fertilization increased the LER of the sole maize and maize + U. ruziziensis intercropping. Maize intercropping had higher LER values with greater demand for nitrogen to obtain similar yields compared to sole maize cropping.

Evaluating the effects of crop successions in no-tillage system (NTS) is essential for the correct recommendation of agronomic practices, such as top-dressing nitrogen fertilization. The aim was to evaluate the effect of the crop succession and the splitting of top-dressing N fertilization on the agronomic performance and economic viability of common bean crop. The experiment was conducted in southeastern Brazil for two agricultural seasons in an area under NTS, using a split-plot in randomized complete block design. The plots represented three cropping successions (maize in sole crop, maize intercropped with Urochloa ruziziensis and U. ruziziensis in sole crop) and the subplots composed of ten combinations of splitting of top-dressing N, at the stages V3, V4 and R5 of the common bean crop. In relation to the single application of the N dose of 90 kg ha−1, the common bean had higher response as a function of the N splitting schemes adopted, regardless of the previous cropping succession. The cropping successions evaluated did not interfere with the seed yield of common bean as subsequent crop, even at the beginning of the establishment of NTS. To obtain higher seed yield and economic viability, the N dose of 90 kg ha−1 indicated for the crop must be split and applied among the phenological stages V3, V4 and R5.

The production and consumption of muskmelon have been increasing (MELO et al., 2014), thus, information on techniques for higher field productions are necessary. The experiment described in the present work was conducted in the IFTM, Uberaba, State of Minas Gerais, Brazil, aiming to evaluate the muskmelon yield under different soil water tensions. A randomized block experimental design was used with five treatments (soil water tensions of 10, 20, 30, 40 and 50 kPa) and four replications (plots of two rows of 14 plants). Two harvests were carried out and the fruit yield, stem diameter, number of fruits per plant and efficiency of water use were evaluated. Irrigation was performed with a drip irrigation system and managed with tensiometry. The cultivar Bonus n.2 was used with spacing of 1.0 x 0.6 m. The data of the variables were subjected to the F test and regression test. The treatments showed statistical differences in number of fruits per plant, fruit weight (fruit yield) and stem diameter. The highest fruit yield found was 1.36 kg fruit -1 and the highest water use efficiency was 4.08 g mm -1 with irrigation for a soil water tension of 10 kPa. The lowest fruit yield was found with irrigation for a soil water tension of 50 kPa.