TY - JOUR AU - Dube, Ernest AU - Chiduza, Cornelius AU - Muchaonyerwa, Pardon PY - 2017/12/13 Y2 - 2024/03/28 TI - High biomass yielding winter cover crops can improve phosphorus availability in soil JF - South African Journal of Science JA - S. Afr. J. Sci. VL - 110 IS - 3/4 SE - Research Article DO - 10.1590/sajs.2014/20130135 UR - https://sajs.co.za/article/view/3772 SP - 1-4 AB - <div style="left: 288.189px; top: 209.543px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.86869);">We investigated the effects of high biomass yielding winter cover crops, namely grazing vetch (</div><div style="left: 870.231px; top: 209.543px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.889714);">Vicia</div><div style="left: 288.189px; top: 230.045px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.86625);">dasycarpa</div><div style="left: 349.501px; top: 230.045px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.856744);">L.) and oats (</div><div style="left: 423.184px; top: 230.045px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.845407);">Avena sativa</div><div style="left: 495.885px; top: 230.045px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.869726);">L.), on soil phosphorus (P) availability in low fertiliser input maize-based</div><div style="left: 288.189px; top: 250.546px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.842969);">conservation agriculture systems. Soil samples were collected from the 0–50-mm depth of experimental</div><div style="left: 288.189px; top: 271.048px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.837396);">plots after 4 years of maize–winter cover crop rotations. A sequential fractionation scheme was used to</div><div style="left: 288.189px; top: 291.549px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.842701);">separate total soil P into labile, moderately labile and non-labile organic P (P</div><div style="left: 739.3991666666666px; top: 302.56702148437495px; font-size: 8.745px; font-family: sans-serif;">o</div><div style="left: 743.622px; top: 291.549px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.84326);">) and inorganic (P</div><div style="left: 850.7099999999999px; top: 302.56702148437495px; font-size: 8.745px; font-family: sans-serif;">i</div><div style="left: 852.452px; top: 291.549px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.84375);">) pools.</div><div style="left: 288.189px; top: 312.05px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.887141);">Labile P pools included microbial biomass-P as well as P</div><div style="left: 616.4273333333333px; top: 323.0683548177083px; font-size: 8.745px; font-family: sans-serif;">i</div><div style="left: 618.17px; top: 312.05px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.88);">and P</div><div style="left: 654.6751666666665px; top: 323.0683548177083px; font-size: 8.745px; font-family: sans-serif;">o</div><div style="left: 658.898px; top: 312.05px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.887409);">pools extracted using 0.5 M NaHCO</div><div style="left: 868.3316666666666px; top: 323.0683548177083px; font-size: 8.745px; font-family: sans-serif;">3</div><div style="left: 872.687px; top: 312.05px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.906563);">and</div><div style="left: 288.189px; top: 332.552px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.877243);">1.0 M HCl. The non-labile P pools were humic-P and 1.0 M H</div><div style="left: 631.1635px; top: 343.5696881510415px; font-size: 8.745px; font-family: sans-serif;">2</div><div style="left: 635.519px; top: 332.552px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.765);">SO</div><div style="left: 652.35px; top: 343.57px; font-size: 8.745px; font-family: sans-serif; transform: scaleX(0.816564);">4</div><div style="left: 658.574px; top: 332.552px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.856145);">extracted P. Soil on the maize–winter cover</div><div style="left: 288.189px; top: 353.053px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.8825);">crop rotations had higher HCl-P</div><div style="left: 468.20133333333325px; top: 364.07118815104155px; font-size: 8.745px; font-family: sans-serif;">i</div><div style="left: 469.944px; top: 353.053px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.888117);">and total P than the soil on the maize–fallow rotation. The cover crops had</div><div style="left: 288.189px; top: 373.555px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.865397);">no significant (</div><div style="left: 376.45966666666664px; top: 373.55464062500005px; font-size: 14.999999999999998px; font-family: sans-serif;">p</div><div style="left: 383.762px; top: 373.555px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.87284);">&gt;0.05) effect on NaHCO</div><div style="left: 531.2631666666666px; top: 384.57252148437493px; font-size: 8.745px; font-family: sans-serif;">3</div><div style="left: 535.619px; top: 373.555px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.86);">-P</div><div style="left: 548.0551666666667px; top: 384.57252148437493px; font-size: 8.745px; font-family: sans-serif;">o</div><div style="left: 552.278px; top: 373.555px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.805952);">, NaHCO</div><div style="left: 603.0493333333334px; top: 384.57252148437493px; font-size: 8.745px; font-family: sans-serif;">3</div><div style="left: 607.405px; top: 373.555px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.86);">-P</div><div style="left: 620.3026666666666px; top: 384.57252148437493px; font-size: 8.745px; font-family: sans-serif;">i</div><div style="left: 622.045px; top: 373.555px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.832059);">, HCl-P</div><div style="left: 664.0121666666666px; top: 384.57252148437493px; font-size: 8.745px; font-family: sans-serif;">o</div><div style="left: 668.235px; top: 373.555px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.848733);">, fulvic acid-P and recalcitrant H</div><div style="left: 859.1978333333332px; top: 384.57252148437493px; font-size: 8.745px; font-family: sans-serif;">2</div><div style="left: 863.553px; top: 373.555px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.765);">SO</div><div style="left: 880.3843333333332px; top: 384.57252148437493px; font-size: 8.745px; font-family: sans-serif;">4</div><div style="left: 884.74px; top: 373.555px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.875526);">-P</div><div style="left: 288.189px; top: 394.056px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.880761);">fractions. Non-application of fertiliser increased accumulation of humic-P on the maize–oats rotation. Cover</div><div style="left: 288.189px; top: 414.558px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.91115);">crop biomass input explained 73% of the variations in microbial biomass-P and 33% of variations in total</div><div style="left: 288.189px; top: 435.059px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.903296);">labile P. Phosphorus concentration of young maize plants was significantly increased by the cover crops,</div><div style="left: 288.189px; top: 455.56px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.894892);">with a positive correlation to HCl-P</div><div style="left: 486.83983333333333px; top: 466.5783548177082px; font-size: 8.745px; font-family: sans-serif;">i</div><div style="left: 488.582px; top: 455.56px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.98);">(</div><div style="left: 497.3966666666666px; top: 455.5603072916666px; font-size: 14.999999999999998px; font-family: sans-serif;">r</div><div style="left: 501.90833333333325px; top: 466.5783548177082px; font-size: 8.745px; font-family: sans-serif;">s</div><div style="left: 505.756px; top: 455.56px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.914376);">=0.90). This contribution from winter cover crops to P availability in</div><div style="left: 288.189px; top: 476.062px; font-size: 15px; font-family: sans-serif; transform: scaleX(0.883172);">the surface soil suggests that, in the long term, fertiliser P could be reduced in such systems.</div> ER -