Effects of preceding compost application on the nitrogen budget in an upland soybean field converted from a rice paddy field on gray lowland soil in Akita, Japan

Abstract

The annual nitrogen (N) budget was measured in a soybean-cultivated upland field during the first year after conversion from a paddy field on gray lowland soil, which is typically found on the Sea of Japan side of northern Japan. Forage rice was cultivated on lysimeter fields for 4 consecutive years with applications of chemical fertilizer, immature compost, or mature compost (the control, immature compost, and mature compost plots, respectively), and then the fields were converted to upland fields for soybean (Glycine max [L.] Merrill cultivar Ryuho) cultivation. Input (seed, bulk N deposition, and symbiotic dinitrogen [N 2 ] fixation) and output (harvested grain, leached N via drainage water, and nitrous oxide emission) N flows were measured, and the field N budget was estimated from the difference between the input and output. The soybean plants in the immature and mature compost plots grew well and had higher yields (498-511 g m ) in the mature compost plot (27.7) was higher than those in the control (18.1) and immature compost plots (19.9). Percentages of soybean N accumulation derived from N 2 fixation ranged from 53% to 74%. N derived from symbiotic N 2 fixation accounted for more than 90% of the total N input, whereas harvested grain accounted for approximately 85% of the total N output. N leaching mainly occurred during the fallow period, accounting for 13-15% of the total N output. The annual N budgets were negative ()10.0, )14.2, and )6.4 g N m )2 year )1for the control, immature compost, and mature compost plots, respectively). The N loss from the immature compost plot was higher than that of the control plot, because the N output in harvested grain was higher, and the N input by N 2 fixation was similar between plots. While the N loss from the mature compost plot was lower than that of the control plot because the N output in harvested grain was higher, as was the case in the immature compost plot, the N input by N 2 fixation was also higher. Preceding compost application--whether immature or mature compost--to paddy fields increased the subsequent soybean yield during the first year after conversion. This result suggests that N loss and the following decrease in soil N availability in the field could be mitigated by increased N 2 fixation resulting from mature compost application with an appropriate application practice.

Changes in the Nitrogen Budget and Soil Nitrogen in a Field with Paddy–Upland Rotation with Different Histories of Manure Application

“…Therefore, the nitrogen budget of soybean cultivation in a rotated paddy field could be negative, indicating nitrogen loss from the field. In fact, negative nitrogen budgets were reported recently in Japanese soybean-cultivated upland fields during the first year after conversion from paddy fields (−10.0 g N m −2 year −1 in Akita [8], −4.0 g N m −2 growing period −1 in Shiga [9]). …”

Decline in Fertility of Paddy Soils Induced by Paddy Rice and Upland Soybean Rotation, and Measures against the Decline

“…In another study, soybean showed a greater rhizosphere priming effect on total soil C efflux as compared with wheat (Triticum aestivum L.) (Cheng et al 2003). Annual N budgets in an upland soybean field converted from a paddy rice field on gray lowland soil were negative, ranging from -14.2 to -6.4 g N/m 2 , because a large quantity of N was removed from the field with harvested soybeans (Takakai et al 2010). In contrast, the N budgets in paddy rice fields (rice cultivation) have been shown to be even or positive (App et al 1984, Kyuma 2004.…”

Net Greenhouse Gas Budget and Soil Carbon Storage in a Field with Paddy–Upland Rotation with Different History of Manure Application

“…All treatments were conducted with one replication (lysimeter). More detailed information is provided in related papers [17,18]. The chemical properties of studied soils (0-10 cm) in each plot are provided in detail by Takakai et al [17].…”

“…More detailed information is provided in related papers [17,18]. The chemical properties of studied soils (0-10 cm) in each plot are provided in detail by Takakai et al [17]. Briefly, the soil pH and cation exchange capacity (CEC) ranged from 5.6 to 6.0 and 21.8 to 23.9 cmol C kg −1 , respectively.…”

“…CH 4 and N 2 O fluxes were measured using a closed-chamber method based on the method described in Takakai et al (for soybean upland [17,18] and rice paddy [18,21]). …”