P. Cull, S. Gishford, R. Johnson
The influence of soil water status on yield and quality of vegetable crops has been well proven in the field by farmers and consultants using the neutron probe over the past two years in Australia and New Zealand.

Precise control over soil water status is possible using trickle and spray irrigation systems which are being used extensively for vegetable crop production. However consultants and farmers in vegetable growing areas at Gatton, Finley and Ballarat have shown that over irrigation leading to loss of water below the root zone is a major cause of poor irrigation efficiency as well as having a direct effect on yield and quality due to its effect on plant nutrient status.

The neutron probe readings, when correlated with petiole nutrient tests have shown that the plant nutrient levels are influenced by soil water status and that knowledge of soil water levels and crop daily water use is essential for correct interpretation of plant nutrient status.

By monitoring soil water status on a regular basis, soil structural problems and inefficiencies in water application can be identified and improved. Then, from the neutron probe readings, critical soil water levels can be established and maintained in conjunction with optimum plant nutrient levels to achieve consistent yield and quality of vegetables at harvest.

Case studies from commercial vegetable crop situations illustrate the importance of regular soil water and plant nutrient measurements for irrigation efficiency and crop yield and quality.

Cull, P., Gishford, S. and Johnson, R. (1989). IRRIGATION MANAGEMENT AND NUTRITION ON VEGETABLES. Acta Hortic. 247, 223-228
DOI: 10.17660/ActaHortic.1989.247.41

Acta Horticulturae