Effect of Barley Straw Application on Soil Properties, Rice Yield and Plowable Stress with Plowing Methods and Irrigation Rates in Barley- Rice Double Cropping System

To reduce both the floatation of the seedling of rice and the failure in standing in the paddy field when the barley straw was applied to paddy field before planting the rice, we tested the effect of rice rooting with plowing methods and irrigation rates for 2 years from 2003 to 2004. This study was carried out in paddy field with Fluvio-Marine deposit in Jeonbug series and the operating accuracy and the change of soil physico-chemical properties depending on plowing methods and irrigation rates following the barley straw applying were examined. There was a less floatation of barley straw in the dry-rotaryI+water-rotaryI(DRI+WRI) plot than in the plowing+water-rotary(PL+WRI) plot. The ratio of miss-planted and floating seedling also decreased by 1.7%, 2.6% in the DRI+WRIplot compared with PL+WRI plot. The soil physical property was improved with the decreasing soil hardness, bulk density and increasing soil porosity after the application of barley straw, especially enhanced greatly in the increase of porosity, gaseous phase and with the decrease of soil hardness, bulk density of subsurface soil in DRI+WRI plot. And the change of soil chemical property were increased the content of total carbon$^{\circ}{\S}$nitrogen$^{\circ}{\S}$organic matter and available phosphate while decreased the content of exchangeable cations and available silicate after the application of barley straw. Also the content of organic matter, available phosphate and cation exchangeable capacity were increased, whereas caron/nitrogen ratio was decreased in DRI+WRI plot compared with PL+WRI plot. The number of panicles, spikelets per square meter were increased and 1,000 grains weight of hulled rice was gained more in DRI+WRI plot at irrigation rate of $500ton\;ha^{-1}$, in DRI+WRII plot at irrigation rate of $700ton\;ha^{-1}$. So the rice yields were increased by 7%, in DRI+WRI and 5% in DRI+WRII plot, respectively compared with PL+WRI plot. The result of this study indicated that the most appropriate plowing method with barley straw application on rice cultivation at double cropping in normal paddy field plain land was DRI+WRI.

이모작 벼 재배시 경운방법 및 관개량에 따른 쌀 수량, 토양특성에 대한 보릿짚 시용효과

답리작 보리재배 후 보릿짚을 시용하고 관개량, 경운방법을 달리하여 만추벼를 전북통에서 2년 동안 재배시 토양이화학성, 작업정도, 생육 및 수량성을 검토한 결과는 다음과 같다. 보릿짚 시용 후 경운방법 및 관개량에 따른 작업정도는 마른로타리 1회 + 물 로타리 1회 처리구에서 경운 + 물 로타리 1회(관행)보다 보릿짚 피복정도가 적었고 결주율 2.6%, 부묘율 1.7% 낮았으며 관개량이 많을수록 결주율과 부묘율이 낮아지는 경향을 나타냈다. 토양이화학성 변화는 마른로타리 1회 + 물 로타리 1회 처리구 심토에서 토양경도, 용적밀도가 낮아지고 공극율, 기상율이 증가되어 토양물리성이 개선되었으며 마른로타리 1회 + 물 로타리 1회 처리구에서 CEC가 높아지고 유기물, 유효인산 함량이 증가되었으며 C/N율이 낮아져 토양화학성이 개량되었다. 경운방법에 따른 벼의 유효경비율은 마른로타리 1회 + 물 로타리 2회 > 마른로타리 1회 + 물 로타리 1회 > 경운 + 물 로타리 1회 > 물 로타리 1회 순으로 높았으며 쌀 수량은 $500Mg\;ha^{-1}$ 관개시 마른로타리 1회 + 물 로타리 1회, $700Mg\;ha^{-1}$ 관개시 마른로타리 1회 + 물 로타리 2회 처리구에서 수수 및 영화수 확보가 많았고 현미천립중이 무거워 경운 + 물 로타리 1회(관행) 대비 각각 7%, 5% 증수되었다.