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植稻土壤排水烤田后迅速降低土壤含水量,而以0—20厘米耕层中变化较大,表土0—5厘米的含水量由烤田前(13/Ⅷ)的54.3%降低到复水前(22/Ⅷ)的39.9%;耕层以下的变化不明显,20—30厘米土层的含水量在8月13日和8月22日相应为27.8%和27.9%,接近于对照(28.3%)。土壤含水量的降低使土壤逐渐由软烂变为板硬。植稻土壤含水量降低可导致土壤容重增大,如含水量增加则减小。初步试用瑞典锥形强度仪测定土壤烂、软、板、硬的结果尚属满意。这个资料不仅可以说明土壤的紧实程度,还可以反映土壤颗粒的相互粘合和植株根系交织的应力。初步摸索采集植稻土壤中空气试样的方法,并对烤田影响土壤空气容量和组成的变化积累了一些资料。烤田可以提高土壤三相比中的气相容积比,耕层土壤可以从5%增加到11%以上。空气组成中氧气的含量随着烤田程度的加深而从5%左右增加到13%以上;复水半月以后仍含有8%左右,比对照的4%左右高出约1倍。CO_2的含量变化不明显,忽高忽低。烤田末期的以CH_4含量减少得很多,只有0.65%,而对照高达14.5%;复水后仍然比对照为低。8月25日和30日烤田的CH_4含量为4.1%与3.27%,对照处理为18.8%与4.5%。渗漏水中溶解氧的含量随着烤田程度的加深而增加,8月4日渗漏水中溶解氧为0.65毫克/升,8月22日增加到1.69毫克/升;对照则维持在0.6—0.8毫克/升。如以灌溉水中6.48毫克/升的氧减去渗漏水中的含量,很明显地说明烤田对溶解氧的消耗量比对照为低。烤田不仅可以升高土壤中氧化还原电位,还可以降低土壤中的有效氮素(氨态氮),但在复水后二者都呈相反的方向变化。土壤温度的变化虽小,但可以提高土壤的日温差,烤田比对照高出一倍多,耕层以下变化不明显。烤田时水稻根系活力降低,但复水后反而加强。水稻伤流量由逐渐降低而后升高,并一直维持着比对照高。烤田可使水稻主茎各节单位长度和干重增大。烤田可以改善土壤的通透性,而导致其他物理、化学、生物特性的变化。深入研究烤田所引起各种性质的改变并分别其主次关系,是揭发烤田作用的重要工作。
Paddy soil quickly drains the soil water content after draining the paddy fields, but varies greatly in the 0-20 cm layer. The water content of the 0-5 cm topsoil is reduced from 54.3% in the former (13 / Ⅷ) to rewatering 39.9% of the former (22 / Ⅷ). The changes below the tillage layer were not obvious. The water content of 20-30 cm soil layer was 27.8% and 27.9% on August 13 and August 22, respectively, which was close to the control (28.3 %). Decreasing soil water content makes the soil gradually change from soft to hard. The reduction of soil water content in paddy rice leads to the increase of soil bulk density, and decreases as the water content increases. The preliminary test Swedish cone strength meter to determine soil rotten, soft, board, hard results are still satisfactory. This data not only shows the degree of compaction of the soil, but also reflects the inter-binding of soil particles and the interlacing stress of the plant roots. The method of collecting air samples from rice soil was initially explored, and some data were accumulated on the changes of soil air capacity and composition affected by soils. Baked fields can increase the volume ratio of gas in three phases of soil, and the topsoil can increase from 5% to 11%. The content of oxygen in the air composition increased from about 5% to over 13% with the deepening of the degree of bake field. After half a month of rehydration, the content of oxygen still contained about 8%, which was about 1 times higher than about 4% of the control. CO 2 content change is not obvious, fluctuated. The content of CH_4 in the late stage of roasting decreased a lot, only 0.65%, while the control was as high as 14.5%. After rehydration, the content of CH_4 was still lower than the control. The CH_4 content in the fields on August 25 and 30 was 4.1% and 3.27%, respectively, and the control treatments were 18.8% and 4.5%. The content of dissolved oxygen in seepage water increased with the deepening of the degree of roasting. The dissolved oxygen in seepage water on August 4 was 0.65 mg / l, increased to 1.69 mg / l on August 22; the control was maintained at 0.6-0.8 Mg / l. If the amount of 6.48 mg / L of oxygen minus the amount of leaking water in the irrigation water clearly shows that the amount of dissolved oxygen consumed in the field is lower than that of the control. Baked fields can not only increase the redox potential of the soil, but also reduce the available nitrogen (ammonia nitrogen) in the soil, but both change in the opposite direction after rehydration. Although the change of soil temperature is small, it can increase the daily temperature difference of soils, and the amount of baked fields is more than double that of the control, and the changes below the tillage layers are not obvious. Grilled rice field when the root activity decreased, but after rehydration but strengthened. Rice injury decreased gradually from then increased, and maintained a higher than the control. Baked fields can make each section of rice stem length and dry weight increase. Baked fields can improve soil permeability, leading to other physical, chemical, biological changes. In-depth study of the bake fields caused by various changes in the nature and their primary and secondary relationships, is to expose the role of baking land important work.