Untitled - MendelNet 2013 - Mendelova zemědělská a lesnická ...

MENDELNET 2013RESULTS AND DISCUSSIONData in table 1 show that there are not any interactions between rice straw burning and plant densityof maize and effect on grain yield and fresh aboveground biomass. However, non- burning of strawbefore planting maize have the tendency to increase grain yield and fresh aboveground biomasswhen compared to the treatments with burning of straw before planting. At the same plant density,spacing of plants 65x20 cm caused higher increase of grain yield compared to the spacing of 65x40cm and 2 plants/hill. It can be explained by the fact that the roots of maize competed for nutrientsand water. Higher plant density caused the decrease of grain yield but there was no effect on freshaboveground biomass.Table 1. The effects of rice straw burning before planting maize and population density of maizeon grain yield and fresh aboveground biomassSpacing Grain yield (kg/ha)Fresh shoot matter (kg/ha)Plants/m 2(cm 2 )Non burning Burning average Non burning Burning average7.69 65x20 5,094 5,213 5,156a 14,872 15,507 15,189a7.69 65x40 4,581 4,556 4,569b 10,453 13,895 15,299a11.54 65x20 4,806 3,938 4,369b 17,094 17,338 17,216aaverage 4,825a 4,569a 4,694 16,223a 15,580a 15,902CV (%) 7.52 16.38Data in table 2 show that there are not any interactions between maize cultivars and rates offertilizers. The highest grain yield was observed in the variant treated with 1,500 kg/ha of organicfertilizer. The SUWAN 4452 which is a hybrid cultivar gave more grain yield when compared toSUWAN 5 which is an opened-pollinated one. Comparison of the costs of maize production in eachvariant (Table 3) showed that the highest gross profit was observed in the variant which usedSUWAN 4452 and applied 1,500 kg/ha of organic fertilizer. Jatupornpong et al. (2009) reportedthat the application of organic fertilizer higher than 1,562.5 kg/ha increased grain yield of fieldcrops.Table 2. The effect of maize cultivars and rates of organic fertilizers on grain yieldGrain yield (kg/ha)Rate of organic fertilizer (kg/ha)SUWAN 5 SUWAN 4452 average0 4,068.8 4,668.8 4,368.8b375 4,281.3 5,062.5 4,671.9b1500 4,525.0 5,906.3 5,215.6aaverage 4,291.7b 5,212.5a 4,752.1cv(%) 8.85154 | P age