We are starting a sizeable produce field this year that was previously used as a crop field. We bought a soil testing kit from Rural King and as best we could tell, we were slightly low on phosphorous, extremely low on nitrogen, and surplus on potash. The ph looked to be neutral. Our question is how do we add the elements we need without increasing the ph? We also need to add calcium, to help our tomatoes. What kinds of calcium could we add without increasing ph? We were thinking about adding oyster shell calcium. What is the difference between pelletized lime and crushed lime? We are going to plant this field in 6 weeks and we need all of the help we can get to get this soil where it needs to be. Also would it be better to go with a slow release fertilizer that can be placed in the soil with transplants? Our field is about 8 acres.

Consider using gypsum. It has some sulfer mixed with the lime to keep it neutral. It needs to be plowed or disked in. Any nitrogen product tends to make soil acidic but since it leaches the ph should not be too bad especially if you use low rates more frequently. Crushed lime should be finer than pelletized therefore it should buffer soil ph higher at a faster rate. As for slow release that varies with the crop and how soon it can be harvested. For example, from seed to harvest, leaf lettuce does not take very many weeks so much of the slow release fertilizer will still be in soil after crop is harvested. For more help contact Maurice Ogutu - his email is ogutu@uiuc.edu