New Zealand lost the toss and were put in to bat, losing their first three wickets for two runs. South Africa were 133 for four when bad light ended play 13 overs early.
''There was a little bit there, but at this time of year the groundsman can only do so much,'' number five Astle, who scored 20, told a news conference.
''There's nothing you can do about it, it's part and parcel of playing cricket. The main thing was that the ball was going both ways.
''I hope I'm not putting any of the South African bowlers down, but I don't think they knew which way it was going either.
''We had a target of about 250, and we fell well short of that,'' Astle said.
Makhaya Ntini took five for 35 and pace partner Dale Steyn three for 43. Astle and Fleming shared 55 for the fourth wicket, New Zealand's biggest partnership.
Astle has not given up hope of New Zealand remaining competitive in the match as they bid to level a series that South Africa lead 1-0.
''We're definitely disappointed, but if we knock over six wickets for 80 to 100 runs next day we're still in the game,'' Astle said.
''I think the wicket will get better once the sun gets on it.'' Ntini knew the pitch would work in his favour. ''It was a favourable pitch for us, we knew if we won the toss we would bowl,'' Ntini said.
''We knew that if we put the ball in the right area, a lot of things could happen.'' Steyn felt South Africa's slim lead of 14 runs was already a significant advantage.
''Anything we can build a lead on is valuable, every run is valuable,'' Steyn told.''It's the kind of wicket where you can lose three or four wickets very quickly.''