ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Influences of Green Manures and N-fertilizer Management on Nutrient Uptakes and Yield of Cassava on a Degraded Sandy Soil)

ผู้เขียน:Pimprapa Sinkumkoon, ดร.ศุภิฌา ธนะจิตต์, รองศาสตราจารย์, ดร.สมชัย อนุสนธิ์พรเพิ่ม, รองศาสตราจารย์, นายเอิบ เขียวรื่นรมณ์, ศาสตราจารย์เกียรติคุณ, Preecha Petprapai, Roongnapa Bowichean

สื่อสิ่งพิมพ์:pdf

Abstract

The effects of green manures combined with nitrogen fertilizer rates on cassava was studied on a Warin soil, having a very sandy nature, in Nakhon Ratchasima province. Three treatments comprising ruzi grass, sun hemp and no green manure incorporation (local weeds) as a control, were tested in a split-plot design. Four nitrogen rates (0, 7.5, 15 and 22.5 kg.rai-1 N) as subplots were also studied. Ruzi grass as well as local weeds (mainly jungle rice, crabgrass and goat buttons) contained the highest potassium content of 2.32 and 2.16%, respectively, whereas sun hemp consisted of the highest nitrogen content (2.11%). The amounts of available nitrogen released from ruzi grass and sun hemp were almost identical (74.69–75.55 mg.kg-1) and significantly higher than that obtained from local weeds (55.72 mg.kg-1). Green manure had a clear effect on the cassava yield and plant nutrient uptake whereas N fertilizer had none. Sun hemp and local weed gave the highest fresh tuber yield (4.01 and 3.65 t.rai-1) and above-ground biomass (1.34 and 1.13 t.rai-1) of cassava while the starch content was likely to be low, especially in the case of using sun hemp as green manure (30.83%). The cassava yield and above-ground biomass tended to increase with no significant difference but the starch content significantly decreased with increasing rates of N fertilizer. Nitrogen applied at the rate of 22.5 kg.rai-1 N gave the highest fresh tuber yield of 3.50 t.rai-1 of the nitrogen only treatments. Sun hemp green manuring followed by the application of N fertilizer at the rate of 15 kg.rai-1 N gave the significantly highest fresh tuber yield of 4.35 t.rai-1 while the lowest amount of 2.13 t.rai-1 was produced by the plot using ruzi grass as green manure without any additional N fertilizer.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 049, Issue 3, May 15 - Jun 15, Page 375 - 389 |  PDF |  Page

ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Green Manuring Effect on Yield of Cassava-Sweet Corn Sequential Cropping on Degraded Sandy Soil, Northeast Thailand)

ผู้เขียน:Roongnapa Bowichean, ดร.ศุภิฌา ธนะจิตต์, รองศาสตราจารย์, ดร.สมชัย อนุสนธิ์พรเพิ่ม, รองศาสตราจารย์, นายเอิบ เขียวรื่นรมณ์, ศาสตราจารย์เกียรติคุณ

สื่อสิ่งพิมพ์:pdf

Abstract

The green manuring effect on cassava-sweet corn sequential cropping was evaluated in a sandy Typic Plinthustult soil in Thailand. The highest fresh biomass was observed for ruzi grass (18.53 t.ha-1) followed by local weeds (14.08 t.ha-1), sword bean (12.69 t.ha-1) and sun hemp (12.39 t.ha-1). Sword bean tended to contain the highest nitrogen content (2.28%) while ruzi grass had the greatest potassium content (2.32%). The control (local weeds) had the highest phosphorus content (0.15%) but released more nitrogen than did the others with 148.65 mg.kg-1 followed by sword bean, sun hemp and ruzi grass (133.83, 92.77 and 59.5 mg.kg-1, respectively). The release of nitrogen was greatest at 2 wk after the incorporation of these green manures and the amount continuously reduced, while the release from local weeds ended before the others. Sun hemp was found the most suitable green manure in cassava-sweet corn sequential cropping on this soil and gave the highest tuber yield (27.19 t.ha-1) and fresh-peeled sweet corn (4.19 t.ha-1) but it gave the lowest starch content (30.13%) of cassava tuber. The incorporation of sword bean gave the lowest cassava yield (13.56 t.ha?1) whereas the lowest amount of sweet corn yield (2 t.ha-1) was obtained from the incorporation of ruzi grass. The three green manure plants showed almost no effect on soil properties due to the soil still having low residual plant nutrients and weak soil structure but ruzi grass tended to improve the soil physical properties more than did sun hemp and sword bean.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 047, Issue 3, May 13 - Jun 13, Page 342 - 357 |  PDF |  Page