EFFECT OF SOME OPERATION CONDITIONS FOR TRACTOR ON SOIL COMPACTION UNDER DIFFERENT AGRICULTURE SYSTEMS - RAS SUDR - SOUTH OF SINAI

One of the most negative effects of the using agricultural machinery under inappropriate operation conditionsis the soil compaction resulting from traffic of tractor wheel on the soil surface during the performance of various agricultural processes. The accumulation of this effect leads to soil degradationand lack of sustainable agricultural development.Therefore, this research aims to reduce soil compaction, prevent soil degradation and achievement sustainable agricultural development by study the effect of some operations conditions for tractor (soil moisture content, forward speed and tires air pressure) under different agriculture systems (traditional agriculture and conservation agriculture). So that the field experiment conducted in Ras Sudr, South of Sinai Governorate (sandy loam soil) at three levels of soil moisture content (15%, 20% and 25%), three levels of tractor forward speed (3, 5 and 7) km/h and three levels of tires air pressure (50, 100 and 150) kPa. The measurements were fuel consumption, tractor wheel slippage, rolling resistance, soil bulk density, soil penetration resistance, average infiltration rate, soil surface sinkage, soil layer deformation and sorghum yield (fresh forage). The results showed that significant effect of all study treatments on soil compaction which, resulting from traffic of the tractortires under two agriculture systems.The results showed that, conservation agriculture system achieved the largest decreasing of power requirements and more resistance to soil compaction compared to the traditional agriculture system. Where, conservation agriculture system decreased fuel consumption, tractor wheel slippage, rolling resistance and soil surface sinkage about of 72%, 75%, 38% and 57% respectively, compared to traditional agriculture system. The results indicated to, soil bulk density and soil penetration resistance increased in both of two agriculture systems in traffic zones compared to no-traffic zones but these increasing in the traditional agriculture system were greater than in the conservation agriculture system. Where the increasing of soil bulk density and soil penetration resistance in traffic zones compared to no-traffic zones were about of 37% and 96% respectively, for traditional agriculture system and about of 15% and 31% respectively, for conservation agriculture system. In general, the results showed that average infiltration rate decreased in traffic zones compared to no-traffic zones for two agriculture systems, but the decreasing in traditional agriculture system was greater than conservation agriculture system. Where, the decreasing of average infiltration rate in traffic zones was about of 62% compared to no-traffic zones for traditional agriculture system and about of 39% for conservation agriculture system. The soil layer deformation measured for three soil layers (0:7, 7:14 and 14:21) cm and the results showed that all soil layers deformation increased in traffic zones but the soil surface layer was the largest increasing in deformation compared to the deeper layers for both of two agriculture systems. The average deformation of the soil layers in conservation agriculture system was lower than in the traditional agriculture system about of 55%. In general, sorghum crop yield affected by increasing soil compaction and its productivity decreased about of 46% and 41% in the traffic zones of tractor tires compared to no-traffic zones for traditional agriculture system and conservation agriculture system respectively. According to the experimental results, the best treatment, which achieved the high resistance to the compaction and the greatest yield of the sorghum crop, was the moisture content 15%, tractor forward speed 7 km/h and tire air pressure 50 kPa. This is the best treatment in the both of agriculture systems but the conservation agriculture system was the best to resistance the soil compaction. Despite the increasing in the crop yield in the traditional agricultural system compared to the conservation agriculture system, about of 5% during one agricultural season, the yield in the conservation system is expected to increase by continuous application to more than one agricultural season.