1573 extractive question-and-answer pairs built from ddSoil Fertility and Fertilizers by Havlin.pdf, published by agritech.tnau.ac.in. Every answer is a verbatim span of text the source prints, and each row carries the passage it sits in, its offset in that passage, the source quote, the page and the location in the document, so any row can be checked against the original. 1129 of the 1573 pairs (71.8%) are explanatory questions and 444 restate a figure. 98.60% of rows pass the corpus quality gate.
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df = desidata.load("soil-fertility-and-fertilizers-by-havlin-question-and-answer-dataset")
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Usable for analysis, but expect some cleaning before you rely on it.
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First 10 of 1,573 rows
| question | answer | context | answer_start | question_type | knowledge_quality_score | source_quote | source_page | source_location | confidence | validation_status |
|---|---|---|---|---|---|---|---|---|---|---|
| What is the estimated cation exchange capacity of pure soil organic matter? | estimated to have a CEC of 100–300 meq/100 g soil | Although the CEC is highly vari- able depending on soil pH, soil OM contributes greatly to total soil CEC. Pure soil OM is estimated to have a CEC of 100–300 meq/100 g soil. CEC of Whole Soil The CEC of a soil is strongly affected by the nature and quantity of clay minerals and OM in the soil (Table 2-1). | 123 | definition | 1.000 | Pure soil OM is estimated to have a CEC of 100–300 meq/100 g soil. | 34 | page=34,block=19 | 0.850 | valid |
| What happens to the CaCO3 equivalent when anion uptake effects are taken into account? | considered, the CaCO3 equivalent is often reduced by ∼50%, which may be too extreme considering the acidity produced with NH4 + uptake | -2, or H2PO4 -2 would neutralize some of the acidity produced from nitrification of NH4 + or oxidation of S (Table 3-3). When anion uptake effects are considered, the CaCO3 equivalent is often reduced by ∼50%, which may be too extreme considering the acidity produced with NH4 + uptake. The extent and rate of soil pH decline with fertilization varies among soils and management. | 151 | definition | 1.000 | When anion uptake effects are considered, the CaCO3 equivalent is often reduced by ∼50%, which may be too extreme considering the acidity produced with NH4 + uptake. | 71 | page=71,block=12 | 0.850 | valid |
| What role does manganese play in plant nutrition and toxicity? | an essential plant nutrient, but at high concentrations can be toxic to plants | Different crop varieties also vary widely in their tolerance to Al+3, where some grasses are quite Al+3 tolerant. Manganese is an essential plant nutrient, but at high concentrations can be toxic to plants. The dominant Mn specie in solution is Mn+2 in equilibrium with MnO2: MnO2 + 4H+ + 2e- N Mn+2 + 2H2O | 127 | definition | 1.000 | Manganese is an essential plant nutrient, but at high concentrations can be toxic to plants. | 78 | page=78,block=0 | 0.850 | valid |
| What process allows some plants to tolerate high aluminum levels by accumulating it in their shoots? | based on observations that some plants tolerate high Al levels through accumulation of Al in the shoot where internal Al detoxification can occur | 76 chapter three soil acidity and alkalinity The mechanisms of Al tolerance include both internal and external processes. The internal mechanism is based on observations that some plants tolerate high Al levels through accumulation of Al in the shoot where internal Al detoxification can occur. For example, Hydrangea (an ornamental plant) flowers turn from red to blue when transplanted to an acid soil, which is due to Al accumulation in the sepals. | 148 | definition | 1.000 | The internal mechanism is based on observations that some plants tolerate high Al levels through accumulation of Al in the shoot where internal Al detoxification can occur. | 85 | page=85,block=0 | 0.850 | valid |
| What is an effective method for applying limestone to acid soils when incorporation is not possible? | not possible, surface application of limestone to acid soils is effective even though the immediate effect occurs only near the soil surface | In no-tillage systems, surface-applied lime every 3 years can be as effective in maintaining surface and subsoil pH as annual lime applications; however, higher lime rates may be needed to effect vertical lime movement. Where incorporation is not possible, surface application of limestone to acid soils is effective even though the immediate effect occurs only near the soil surface. Compared to conventional tillage systems where lime incorporation is fea- sible, more frequent applications are necessary in no-till systems to maintain soil pH with depth. | 243 | definition | 1.000 | Where incorporation is not possible, surface application of limestone to acid soils is effective even though the immediate effect occurs only near the soil surface. | 98 | page=98,block=7 | 0.850 | valid |
| What disease affects cole crops by reducing yields and distorting roots? | a disease of cole crops that reduces yields and causes infected roots to enlarge and become distorted | Liming has a significant role in the control of certain plant pathogens. Clubroot is a disease of cole crops that reduces yields and causes infected roots to enlarge and become distorted. Lime does not directly affect the clubroot organism, but at soil pH 7 7 germi- nation of clubroot spores is inhibited (Table 3-23). | 85 | definition | 1.000 | Clubroot is a disease of cole crops that reduces yields and causes infected roots to enlarge and become distorted. | 103 | page=103,block=0 | 0.850 | valid |
| What action is required if gypsum is not present in the soil? | not present, it or some similar material may have to be added | If there is plenty of gypsum in the soil, a serious problem may not develop for some time. If gypsum is not present, it or some similar material may have to be added. Very-high-sodium water is generally unsatis- factory for irrigation except at low- or medium- salinity levels, where the use of gypsum or some other amendment makes it possible to use such water. | 104 | definition | 1.000 | If gypsum is not present, it or some similar material may have to be added. | 121 | page=121,block=54 | 0.850 | valid |
| What happens to salt when ridge-tillage systems are used? | used, the salt moves upward with capillary H2O and is deposited on the center of the ridges where the water evaporates | Managing soils for improved drainage is essential for controlling soil salinity. When ridge-tillage systems are used, the salt moves upward with capillary H2O and is deposited on the center of the ridges where the water evaporates. Planting on the shoulders or edge of the ridges helps to avoid problems associated with excess salts (Fig. | 112 | definition | 1.000 | When ridge-tillage systems are used, the salt moves upward with capillary H2O and is deposited on the center of the ridges where the water evaporates. | 122 | page=122,block=0 | 0.850 | valid |
| What role do plant seedlings play in relation to atmospheric ammonia? | a natural sink for atmospheric NH3, absorbing about 40% of the NH3 from air con- taining 1 ppm NH3 | nitrogen chapter four 165 Field crops exposed to air containing normal levels of atmospheric NH3 may obtain 5–10% of their N requirement by direct absorption of NH3. Plant seedlings are a natural sink for atmospheric NH3, absorbing about 40% of the NH3 from air con- taining 1 ppm NH3. NH3 produced near the ground surface of grass-clover pasture can be completely absorbed by the plant cover. | 186 | definition | 1.000 | Plant seedlings are a natural sink for atmospheric NH3, absorbing about 40% of the NH3 from air con- taining 1 ppm NH3. | 174 | page=174,block=0 | 0.850 | valid |
| What is the issue with biuret in most urea products? | not a problem in most urea products | Urea high in biuret should not be placed near or in the seed row. Biuret is not a problem in most urea products. As discussed in the previous section (Volatilization of NH3), careful manage- ment of urea and urea-based fertilizers will reduce the potential for NH3 volatiliza- tion losses and increase effectiveness of urea fertilizers. | 76 | definition | 1.000 | Biuret is not a problem in most urea products. | 176 | page=176,block=3 | 0.850 | valid |
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