苜蓿用鉀肥ppt課件(編輯修改稿)
2025-02-13 09:55 本頁面
【文章內(nèi)容簡介】 m Response to K Increases Over Life of Stand Berg et al., 2022 (IN) 051015202530350 100 200 300 400Cumulative yield, ton/A1998 1999 2022 2022 2022Added K, lb K2O/A Greatest response occurred in 5th year Response to K Increases Over Life of Stand 67890 1 0 0 2 0 0 3 0 0 4 0 0 5 0 02 . 02 . 53 . 03 . 5Yield, tons/A Fertilizer K2O, lb/A Forage K, % Most Economic Rate 1985 1986 Sheard et al., 1988 (ON) 1985 1986 Response increases after intensive management ? Alfalfa response to K under intensive 5cut management ? Initial soil test K of 170 ppm in 1984, declined to 80 ppm in the unfertilized treatment by spring 1987 Soil K Levels: Turn K Fertilization into Profit Example: Annual economic return to K fertilizer use: Assuming $90 per ton of hay and K2O at $ per pound (price ratio of 3 lb hay per lb of K2O) Soil test K category Yield response K2O rate Net return tons/A lb/A $/A Very low 335 Low 260 High 90 Economics of K Fertilization The most economic rate of K fertilization changes as the ratio of K prices to hay prices changes Soil Test K Price Ratio Category 2 3 4 5 Most economic rate of K2O (lb/A) Very low 425 335 270 220 Low 330 260 214 175 High 130 90 60 40 Profitability: Short vs. LongTerm The yield increase in response to K application gets larger as the alfalfa stand ages A l f a l f a Y i e l d R e s p o n s e t o A n n u a l l y A p p l i e d K0 . 00 . 51 . 01 . 52 . 02 . 51 2 3 4 5 6 7A g e o f s t a n d , y e a r sYield response, tons/AQ u e b e cP e n n sy l v a n i aN e w Y o r kM a n i t o b aM i ss o u r iBurmester et al., 1991 (AL) 0481216120 240 440 550 640 K2O application rate, lb/A Alfalfa stand density, plants/ft2 K Fertilization According to Soil Test Remendation Maintains Alfalfa Stands Remended K rate Follet and Wilkinson, 1995 0 1 2 3 5 6 7 Soil pH Yield, tons/A 苜蓿產(chǎn)量受土壤 PH影響 Walworth and Sumner, 1990 (GA) 石灰中和酸性土壤改善苜蓿生長并提高營養(yǎng)恢復(fù) 024680 2100 3400
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